KLATSID
Interaction
The following drugs are contraindicated in combination with clarithromycin due to the potential for serious side effects:
Cisapride, pimozide, terfenadine and astemizole
When clarithromycin was co-administered with cisapride, pimozide, terfenadine or astemizole, increased plasma concentrations of the latter were reported, which could lead to QT prolongation and cardiac arrhythmias, including ventricular tachycardia, ventricular fibrillation and torsade de pointes (TdP) (see section "Contraindications")
Ergot alkaloids
Post-marketing studies show that when clarithromycin is used together with ergotamine or dihydroergotamine, the following effects associated with acute poisoning with ergotamine drugs are possible: vascular spasm, ischemia of the limbs and other tissues, including the central nervous system. Concomitant use of clarithromycin with ergot alkaloids is contraindicated (see section “Contraindications”).
HMG-CoA reductase inhibitors (statins)
Concomitant use of clarithromycin with lovastatin or simvastatin is contraindicated (see section "Contraindications") due to the fact that these statins are largely metabolized by the CYP3A4 isoenzyme, and combined use with clarithromycin increases their serum concentrations, which leads to an increased risk of developing myopathy, including Rhabdomyolysis Cases of rhabdomyolysis have been reported in patients taking clarithromycin concomitantly with these drugs. If clarithromycin is necessary, lovastatin or simvastatin should be discontinued during therapy.
Clarithromycin should be used with caution in combination therapy with other statins. It is recommended to use statins that are independent of the metabolism of the CYP3A isoenzyme (for example, fluvastatin). If coadministration is necessary, it is recommended to take the lowest dose of statin. The development of signs and symptoms of myopathy should be monitored.
Effect of other drugs on clarithromycin
Drugs that are inducers of the CYP3A isoenzyme
(for example, rifampicin, phenytoin, carbamazepine, phenobarbital, St. John's wort) may induce the metabolism of clarithromycin. This may result in subtherapeutic concentrations of clarithromycin, resulting in reduced effectiveness. In addition, it is necessary to monitor the concentration of the CYP3A inducer in the blood plasma, which may increase due to the inhibition of the CYP3A isoenzyme by clarithromycin. When rifabutin and clarithromycin were used together, an increase in plasma concentrations of rifabutin and a decrease in serum concentrations of clarithromycin were observed with an increased risk of developing uveitis.
The following drugs have a proven or suspected effect on clarithromycin plasma concentrations; if used together with clarithromycin, dosage adjustments or switching to alternative treatment may be required
Efavirenz, nevirapine, rifampicin, rifabutin and rifapentine
Strong inducers of the cytochrome P450 system, such as efavirenz, nevirapine, rifampicin, rifabutin and rifapentine, can accelerate the metabolism of clarithromycin and, thus, reduce the plasma concentration of clarithromycin and weaken the therapeutic effect, and at the same time increase the concentration of 14-OH-clarithromycin, a metabolite. also being microbiologically active. Since the microbiological activity of clarithromycin and 14-OH-clarithromycin differs against different bacteria, the therapeutic effect may be reduced when clarithromycin is used together with enzyme inducers.
Etravirine
The concentration of clarithromycin decreases with the use of etravirine, but the concentration of the active metabolite 14-OH-clarithromycin increases. Because 14-OH-clarithromycin has little activity against Mycobacterium avium complex (MAC) infections, overall activity against these pathogens may be altered, and alternative treatments should be considered for the treatment of MAC.
Fluconazole
Coadministration of fluconazole 200 mg daily and clarithromycin 500 mg twice daily in 21 healthy volunteers resulted in an increase in the mean clarithromycin minimum steady-state concentration (Cmin) and AUC by 33% and 18%, respectively. However, co-administration did not significantly affect the average steady-state concentration of the active metabolite 14-OH-clarithromycin. No dose adjustment of clarithromycin is required when taking fluconazole concomitantly.
Ritonavir
A pharmacokinetic study showed that coadministration of ritonavir 200 mg every eight hours and clarithromycin 500 mg every 12 hours resulted in a marked suppression of the metabolism of clarithromycin. When co-administered with ritonavir, clarithromycin Cmax increased by 31%, Cmin increased by 182% and AUC increased by 77%. Complete suppression of the formation of 14-OH-clarithromycin was noted. Due to the wide therapeutic range of clarithromycin, dose reduction is not required in patients with normal renal function. In patients with renal failure, it is advisable to consider the following dose adjustment options: with CC 30-60 ml/min, the dose of clarithromycin should be reduced by 50%; with CC less than 30 ml/min, the dose of clarithromycin should be reduced by 75%. Ritonavir should not be co-administered with clarithromycin in doses exceeding 1 g/day.
Effect of clarithromycin on other drugs
Antiarrhythmic drugs (quinidine and disopyramide)
Ventricular tachycardia of the “pirouette” type may occur with the combined use of clarithromycin and quinidine or disopyramide. When clarithromycin is coadministered with these drugs, the electrocardiogram should be regularly monitored for prolongation of the QT interval, and serum concentrations of these drugs should also be monitored.
During post-marketing use, cases of hypoglycemia have been reported during co-administration of clarithromycin and disopyramide. It is necessary to monitor the concentration of glucose in the blood while using clarithromycin and disopyramide.
Oral hypoglycemic agents/insulin
When clarithromycin is used together with oral hypoglycemic agents (for example, sulfonylureas) and/or insulin, severe hypoglycemia may occur. Concomitant use of clarithromycin with certain hypoglycemic drugs (for example, nateglinide, pioglitazone, repaglinide and rosiglitazone) may lead to inhibition of the CYP3A isoenzyme by clarithromycin, which may result in hypoglycemia. Careful monitoring of glucose concentrations is recommended.
Interactions due to CYP3A isoenzyme
Co-administration of clarithromycin, which is known to inhibit the CYP3A isoenzyme, and drugs primarily metabolized by the CYP3A isoenzyme, may be associated with a mutual increase in their concentrations, which may increase or prolong both therapeutic and side effects. Clarithromycin should be used with caution in patients receiving drugs that are substrates of the CYP3A isoenzyme, especially if these drugs have a narrow therapeutic index (for example, carbamazepine) and/or are extensively metabolized by this enzyme. If necessary, the dose of the drug taken together with clarithromycin should be adjusted. Also, whenever possible, serum concentrations of drugs primarily metabolized by the CYP3A isoenzyme should be monitored.
The following drugs/classes are metabolized by the same CYP3A isoenzyme as clarithromycin, for example, alprazolam, carbamazepine, cilostazol, cyclosporine, disopyramide, methylprednisolone, midazolam, omeprazole, indirect anticoagulants (eg, warfarin), quinidine, rifabutin, sildenafil, tacrolimus, triazolam and vinblastine. Also, agonists of the CYP3A isoenzyme include the following drugs that are contraindicated for combined use with clarithromycin: astemizole, cisapride, pimozide, terfenadine, lovastatin, simvastatin and ergot alkaloids (see section “Contraindications”). Drugs that interact in a similar way through other isoenzymes within cytochrome P450 systems include phenytoin, theophylline and valproic acid.
Indirect anticoagulants
When taking warfarin and clarithromycin together, bleeding and a marked increase in INR and prothrombin time are possible. In case of combined use with warfarin or other indirect anticoagulants, it is necessary to monitor the INR and prothrombin time.
Omeprazole
Clarithromycin (500 mg every 8 hours) was studied in healthy adult volunteers in combination with omeprazole (40 mg daily). When clarithromycin and omeprazole were co-administered, steady-state plasma concentrations of omeprazole were increased (Cmax, AUC0-24 and T1/2 increased by 30%, 89% and 34%, respectively). The mean 24-hour gastric pH was 5.2 when omeprazole was taken alone and 5.7 when omeprazole was taken with clarithromycin.
Sildenafil, tadalafil and vardenafil
Each of these phosphodiesterase inhibitors is metabolized, at least in part, by the CYP3A isoenzyme. At the same time, the CYP3A isoenzyme can be inhibited in the presence of clarithromycin. Concomitant use of clarithromycin with sildenafil, tadalafil or vardenafil may result in increased phosphodiesterase inhibitory effects. When using these drugs together with clarithromycin, consider reducing the dose of sildenafil, tadalafil and vardenafil.
Theophylline, carbamazepine
When clarithromycin and theophylline or carbamazepine are used together, the concentration of these drugs in the systemic circulation may increase.
Tolterodine
The primary metabolism of tolterodine occurs through the 2D6 isoform of cytochrome P450 (CYP2D6). However, in part of the population lacking the CYP2D6 isoenzyme, metabolism occurs through the CYP3A isoenzyme. In this population, inhibition of CYP3A results in significantly higher serum tolterodine concentrations. In populations that are poor metabolizers of CYP2D6, a dose reduction of tolterodine may be required in the presence of CYP3A inhibitors such as clarithromycin.
Benzodiazepines (eg, alprazolam, midazolam, triazolam)
When midazolam was co-administered with clarithromycin tablets (500 mg twice daily), midazolam AUC increased by 2.7 times after intravenous midazolam and 7 times after oral administration. Concomitant use of clarithromycin with oral midazolam is contraindicated. If intravenous midazolam is used concomitantly with clarithromycin, the patient's condition should be carefully monitored for possible dose adjustment. The same precautions should be applied to other benzodiazepines that are metabolized by CYP3A, including triazolam and alprazolam. For benzodiazepines whose elimination is not dependent on the CYP3A isoenzyme (temazepam, nitrazepam, lorazepam), a clinically significant interaction with clarithromycin is unlikely.
When clarithromycin and triazolam are used together, effects on the central nervous system (CNS), such as drowsiness and confusion, are possible. Therefore, if coadministration occurs, it is recommended to monitor for symptoms of CNS impairment.
Interactions with other drugs
Aminoglycosides
When taking clarithromycin concomitantly with other ototoxic drugs, especially aminoglycosides, caution should be exercised and the functions of the vestibular and auditory systems should be monitored both during and after therapy.
Colchicine
Colchicine is a substrate of both CYP3A and the P-glycoprotein (Pgp) transporter protein. It is known that clarithromycin and other macrolides are inhibitors of the CYP3A and Pgp isoenzymes. When clarithromycin and colchicine are taken together, inhibition of Pgp and/or CYP3A may result in increased effects of colchicine. The development of clinical symptoms of colchicine poisoning should be monitored. There have been post-marketing reports of cases of colchicine poisoning when taken concomitantly with clarithromycin, most often in elderly patients.
Some of the reported cases occurred in patients suffering from kidney failure. Some cases were reported to be fatal.
The simultaneous use of clarithromycin and colchicine is contraindicated (see section “Contraindications”).
Digoxin
Digoxin is suspected to be a Pgp substrate. Clarithromycin is known to inhibit Pgp. When clarithromycin and digoxin are co-administered, inhibition of Pgp by clarithromycin may result in increased effects of digoxin. Coadministration of digoxin and clarithromycin may also result in increased serum concentrations of digoxin. Some patients have experienced clinical symptoms of digoxin toxicity, including potentially fatal arrhythmias. Serum digoxin concentrations should be carefully monitored when clarithromycin and digoxin are coadministered.
Zidovudine
Concomitant use of clarithromycin tablets and oral zidovudine by adult HIV-infected patients may result in decreased steady-state zidovudine concentrations.
Because clarithromycin interferes with the oral absorption of zidovudine, the interaction can be largely avoided by taking clarithromycin and zidovudine 4 hours apart.
This interaction was not observed in HIV-infected children taking clarithromycin pediatric suspension with zidovudine or dideoxyinosine. Since clarithromycin may interfere with the absorption of zidovudine when administered concomitantly orally in adult patients, such an interaction is unlikely to occur when clarithromycin is used intravenously.
Phenytoin and valproic acid
There is evidence of interactions between CYP3A inhibitors (including clarithromycin) and drugs that are not metabolized by CYP3A (phenytoin and valproic acid). For these drugs, when used together with clarithromycin, it is recommended to determine their serum concentrations, as there are reports of their increase.
Bidirectional drug interactions
Atazanavir
Clarithromycin and atazanavir are both substrates and inhibitors of the CYP3A isoenzyme. There is evidence of a bidirectional interaction between these drugs.
Coadministration of clarithromycin (500 mg twice daily) and atazanavir (400 mg once daily) may result in a twofold increase in clarithromycin exposure and a 70% decrease in 14-OH-clarithromycin exposure, with a 28% increase in atazanavir AUC. Due to the wide therapeutic range of clarithromycin, dose reduction is not required in patients with normal renal function. In patients with moderate renal failure (creatinine clearance 30-60 ml/min), the dose of clarithromycin should be reduced by 50%. In patients with CC less than 30 ml/min, the dose of clarithromycin should be reduced by 75% using the appropriate dosage form of clarithromycin. Clarithromycin in doses exceeding 1000 mg per day should not be used in conjunction with protease inhibitors.
Blockers of "slow" calcium channels
When using clarithromycin simultaneously with blockers of “slow” calcium channels that are metabolized by the CYP3A4 isoenzyme (for example, verapamil, amlodipine, diltiazem), caution should be exercised as there is a risk of arterial hypotension. Plasma concentrations of clarithromycin, as well as slow calcium channel blockers, may increase with simultaneous use. Arterial hypotension, bradyarrhythmia and lactic acidosis are possible when taking clarithromycin and verapamil simultaneously.
Itraconazole
Clarithromycin and itraconazole are substrates and inhibitors of the CYP3A isoenzyme, which determines the bidirectional interaction of the drugs. Clarithromycin may increase plasma concentrations of itraconazole, while itraconazole may increase plasma concentrations of clarithromycin. Patients taking itraconazole and clarithromycin concomitantly should be closely monitored for symptoms of increased or prolonged pharmacological effects of these drugs.
Saquinavir
Clarithromycin and saquinavir are substrates and inhibitors of the CYP3A isoenzyme, which determines the bidirectional interaction of the drugs. Concomitant administration of clarithromycin (500 mg twice daily) and saquinavir (soft gelatin capsules, 1200 mg three times daily) in 12 healthy volunteers increased the AUC and Cmax of saquinavir by 177% and 187%, respectively, compared with saquinavir administration alone. separately. The AUC and Cmax values of clarithromycin were approximately 40% higher than with clarithromycin monotherapy. When these two drugs are used together for a limited time at the doses/formulations indicated above, no dose adjustment is required. Results from drug interaction studies using saquinavir soft gelatin capsules may not be consistent with the effects observed with saquinavir hard gelatin capsules. The results of drug interaction studies with saquinavir monotherapy may not be consistent with the effects observed with saquinarine/ritonavir therapy. When taking saquinavir with ritonavir, consider the potential effect of ritonavir on clarithromycin.
Klacid 250 mg 10 pcs. film-coated tablets
pharmachologic effect
Antibacterial, bacteriostatic.
Composition and release form Klacid 250 mg 10 pcs. film-coated tablets
Film-coated tablets - 1 tablet:
- Active ingredients: clarithromycin - 2500 mg;
- Excipients: croscarmellose sodium - 35 mg, microcrystalline cellulose - 85 mg, pregelatinized starch - 65 mg, silicon dioxide - 7.2 mg, povidone - 20 mg, stearic acid - 12.5 mg, magnesium stearate - 7.5 mg, talc - 17.5 mg, quinoline yellow (E104) - 0.3 mg;
- Film shell composition: hypromellose - 13 mg, hydroxypropylcellulose (hyprolose) - 1 mg, propylene glycol - 8.6 mg, sorbitan monooleate - 1 mg, titanium dioxide - 3 mg, sorbic acid - 0.55 mg, vanillin - 0.55 mg, quinoline yellow (E104) - 0.8 mg.
7, 10 or 14 pcs. - blisters (1, 2, 3) - cardboard packs.
Description of the dosage form
Light yellow, oval, biconvex film-coated tablets.
Directions for use and doses
Inside, regardless of food intake.
Typically, adults are prescribed 250 mg of clarithromycin 2 times a day. In more severe cases, the dose is increased to 500 mg 2 times a day. Typically, the duration of treatment is from 5–6 to 14 days.
Patients with creatinine Cl less than 30 ml/min are prescribed half the usual dose of clarithromycin, i.e. 250 mg 1 time per day, or for more severe infections - 250 mg 2 times per day. Treatment of such patients continues for no more than 14 days.
For mycobacterial infections, 500 mg of the drug is prescribed 2 times a day.
For common MAC infections in patients with AIDS: Treatment should be continued as long as there is clinical and microbiological evidence of benefit. Clarithromycin should be prescribed in combination with other antimicrobial drugs.
For infectious diseases caused by mycobacteria, except tuberculosis: the duration of treatment is determined by the doctor.
For the prevention of infections caused by MAC. The recommended dose of clarithromycin for adults is 500 mg 2 times a day.
For odontogenic infections, the dose of clarithromycin is 250 mg 2 times a day for 5 days.
For eradication of H. pylori
Combination treatment with three drugs
Clarithromycin at a dose of 500 mg 2 times a day in combination with lansoprazole at a dose of 30 mg 2 times a day and amoxicillin at a dose of 1000 mg 2 times a day for 10 days.
Clarithromycin at a dose of 500 mg 2 times a day in combination with amoxicillin at a dose of 1000 mg 2 times a day and omeprazole at a dose of 20 mg/day for 7–10 days.
Combination treatment with two drugs
Clarithromycin at a dose of 500 mg 3 times a day in combination with omeprazole at a dose of 40 mg/day for 14 days, followed by omeprazole at a dose of 20–40 mg/day for the next 14 days.
Clarithromycin at a dose of 500 mg 3 times a day in combination with lansoprazole at a dose of 60 mg/day for 14 days. For complete healing of the ulcer, additional reduction in the acidity of gastric juice may be required.
Pharmacodynamics
Clarithromycin is a semisynthetic antibiotic of the macrolide group and has an antibacterial effect by interacting with the 50S ribosomal subunit of sensitive bacteria and inhibiting protein synthesis.
Clarithromycin has demonstrated high in vitro activity against standard and isolated bacterial cultures. Highly effective against many aerobic and anaerobic, gram-positive and gram-negative microorganisms.
Clarithromycin is highly effective in vitro against Legionella pneumophila, Mycoplasma pneumoniae and Helicobacter (Campilobacter) pylori. Enterobacteriaceae and Pseudomonas, as well as other non-lactose-degrading gram-negative bacteria, are not sensitive to clarithromycin.
Clarithromycin has been shown to have an antibacterial effect against the following pathogens: aerobic gram-positive microorganisms - Staphylococcus aureus, Streptococcus pneumoniae, Streptococcus pyogenes, Listeria monocytogenes; aerobic gram-negative microorganisms: Haemophilus influenzae, Haemophilus parainftuenzae, Moraxella catarrhalis, Legionella pneumophila, Neisseria gonorrhoeae; other microorganisms - Mycoplasma pneumoniae, Chlamydia pneumoniae (TWAR), Chlamydia trachomatis; mycobacteria - Mycobacterium leprae, Mycobacterium kansasii, Mycobacterium chelonae, Mycobacterium fortuitum; Mycobacterium avium complex (MAC) - a complex including: Mycobacterium avium, Mycobacterium intracellulare.
The production of beta-lactamase does not affect the activity of clarithromycin.
Most strains of staphylococci resistant to methicillin and oxacillin are also resistant to clarithromycin.
Helicobacter pylori. The sensitivity of H. pylori to clarithromycin was studied on H. pylori isolates isolated from 104 patients before starting drug therapy. In 4 patients, strains of H. pylori were isolated that were resistant to clarithromycin, in 2, strains with intermediate resistance were isolated, and in the remaining 98 patients, H. pylori isolates were sensitive to clarithromycin. Clarithromycin is effective in vitro and against most strains of the following microorganisms (however, the safety and effectiveness of the use of clarithromycin in clinical practice has not been confirmed by clinical studies and the practical significance remains unclear):
- aerobic gram-positive microorganisms - Streptococcus agalactiae, Streptococci (groups C,F,G), Viridans group streptococci;
- aerobic gram-negative microorganisms - Bordetella pertussis, Pasteurella multocida;
- anaerobic gram-positive microorganisms - Clostridium perfringens, Peptococcus niger, Propionibacterium acnes;
- anaerobic gram-negative microorganisms - Bacteroides melaninogenicus;
- spirochetes - Borrelia burgdorferi, Treponema pallidum;
- campylobacter - Campylobacter jejuni.
The main metabolite of clarithromycin in the human body is the microbiologically active metabolite - 14-hydroxyclarithromycin (14-OH-clarithromycin). The microbiological activity of the metabolite is the same as that of the parent substance, or 1–2 times weaker against most microorganisms. The exception is H.influenzae, for which the effectiveness of the metabolite is 2 times higher. The parent substance and its major metabolite have either additive or synergistic effects against H. influenzae in vitro and in vivo, depending on the bacterial culture.
Sensitivity studies
Quantitative methods that require measuring the diameter of the growth inhibition zone of microorganisms provide the most accurate estimates of the sensitivity of bacteria to antimicrobial agents.
One recommended susceptibility testing procedure uses discs soaked in 15 μg of clarithromycin (Kirby-Bauer diffusion test); the test results are interpreted depending on the diameter of the zone of growth inhibition of the microorganism and the MIC value of clarithromycin. The MIC value is determined by diluting the medium or diffusion into agar.
Laboratory tests give one of 3 results:
- resistant - we can assume that the infection cannot be treated with this drug;
- moderately sensitive - the therapeutic effect is ambiguous, and possibly increasing the dosage may lead to sensitivity;
- sensitive - the infection can be considered treatable with clarithromycin.
Pharmacokinetics
The drug is quickly absorbed into the gastrointestinal tract. Absolute bioavailability is about 50%. With repeated doses of the drug, no accumulation was detected, and the nature of metabolism in the human body did not change. Eating immediately before taking the drug increased the bioavailability of the drug by an average of 25%.
Clarithromycin can be taken before or with meals.
In vitro
In in vitro studies, the binding of clarithromycin to plasma proteins was 70% at concentrations from 0.45 to 4.5 μg/ml. At a concentration of 45 μg/ml, binding decreases to 41%, probably as a result of saturation of binding sites. This is observed only at concentrations many times higher than the therapeutic value.
Healthy
When clarithromycin was prescribed at a dose of 250 mg 2 times a day, the maximum Css of clarithromycin and 14-hydroxyclarithromycin in plasma were reached after 2–3 days and were 1 and 0.6 μg/ml, respectively. T1/2 of the parent drug and its main metabolite were 3–4 and 5–6 hours, respectively. When clarithromycin was prescribed at a dose of 500 mg 2 times a day, the maximum Css of clarithromycin and 14-hydroxyclarithromycin in plasma were achieved after taking the 5th dose and amounted to on average 2.7–2.9 and 0.88–0.83 μg/ml, respectively. T1/2 of the parent drug and its main metabolite were 4.5–4.8 hours and 6.9–8.7 hours, respectively.
At steady state, the level of 14-hydroxyclarithromycin does not increase in proportion to clarithromycin doses, and T1/2 of clarithromycin and its main metabolite increase with increasing dose. The nonlinear nature of the pharmacokinetics of clarithromycin is associated with a decrease in the formation of 14-OH- and N-demethylated metabolites when using higher doses, which indicates the nonlinearity of the metabolism of clarithromycin when taking high doses. About 37.9% are excreted in the urine after taking 250 mg and 46% after taking 1200 mg of clarithromycin, and through the intestines - about 40.2 and 29.1%, respectively.
Clarithromycin and its 14-OH metabolite are well distributed into tissues and body fluids. After oral administration of clarithromycin, its content in the cerebrospinal fluid remains low (with normal BBB permeability of 1–2% of serum levels). The content in tissues is usually several times higher than the content in blood serum.
The table provides examples of tissue and serum concentrations.
Concentrations (250 mg every 12 hours)
Fabrics | Concentrations | |
Tissue, µg/g | Serum, mcg/ml | |
Tonsils | 1,6 | 0,8 |
Lungs | 8,8 | 1,7 |
In patients with moderate to severe impairment of liver function, but with preserved renal function, no dose adjustment of clarithromycin is required. Css in blood plasma and systemic clearance of clarithromycin do not differ between patients in this group and healthy patients. Css of 14-hydroxyclarithromycin in people with impaired liver function is lower than in healthy people.
Renal dysfunction
If renal function is impaired, the minimum and maximum levels of clarithromycin in the blood plasma, T1/2, AUC of clarithromycin and 14-OH metabolite increase. The elimination constant and urinary excretion decrease. The degree of changes in these parameters depends on the degree of renal dysfunction.
Elderly patients
In elderly patients, the level of clarithromycin and its 14-OH metabolite in the blood was higher, and elimination was slower than in the group of young people. It is believed that changes in pharmacokinetics in elderly patients are associated primarily with changes in creatinine clearance and renal function, and not with the age of the patients.
Patients with mycobacterial infections
Css of clarithromycin and 14-OH-clarithromycin in patients with HIV infection who received clarithromycin in usual doses (500 mg 2 times a day) were similar to those in healthy people. However, when clarithromycin is used in higher doses, which may be required to treat mycobacterial infections, antibiotic concentrations may be significantly higher than usual.
In patients with HIV infection taking clarithromycin at a dose of 1000 and 2000 mg/day in 2 divided doses, Css were usually 2–4 and 5–10 μg/ml, respectively. When using the drug in higher doses, a prolongation of T1/2 was observed compared with that in healthy people receiving clarithromycin in usual doses. The increase in plasma concentrations and T1/2 duration when clarithromycin is prescribed at higher doses is consistent with the known nonlinearity of the pharmacokinetics of the drug.
Combination treatment with omeprazole
Clarithromycin 500 mg 3 times a day in combination with omeprazole at a dose of 40 mg/day increases T1/2 and AUC0-24 of omeprazole. In all patients receiving combination therapy, compared with those receiving omeprazole alone, there was an 89% increase in AUC0-24 and a 34% increase in T1/2 of omeprazole. For clarithromycin, Cmax, Cmin and AUC0-8 increased by 10, 27 and 15%, respectively, compared with data when clarithromycin alone was used without omeprazole. At steady state, clarithromycin concentrations in the gastric mucosa 6 hours after dosing in the group receiving the combination were 25 times higher than those in those receiving clarithromycin alone. Concentrations of clarithromycin in gastric tissue 6 hours after taking 2 drugs were 2 times higher than the data obtained in the group of patients receiving only clarithromycin.
Indications for use Klacid 250 mg 10 pcs. film-coated tablets
- lower respiratory tract infections (such as bronchitis, pneumonia);
- upper respiratory tract infections (such as pharyngitis, sinusitis);
- infections of the skin and soft tissues (such as folliculitis, inflammation of the subcutaneous tissue, erysipelas);
- mycobacterial infections caused by Mycobacterium avium and Mycobacterium intracellulare. Localized infections caused by Mycobacterium chelonae, Mycobacterium fortuitum and Mycobacterium kansasii;
- prevention of the spread of infection caused by Mycobacterium avium complex (MAC). HIV-infected patients with a CD4 lymphocyte count (T-helper lymphocytes) of no more than 100 per 1 mm3;
- to eliminate H. pylori and reduce the frequency of relapses of duodenal ulcers;
- odontogenic infections.
Contraindications
- hypersensitivity to macrolide drugs;
- simultaneous use of clarithromycin with the following drugs: astemizole, cisapride, pimozide, terfenadine, ergotamine, dihydroergotamine;
- porphyria;
- pregnancy;
- lactation period;
- children under 3 years of age.
With caution: impaired liver and kidney function.
Clarithromycin is eliminated primarily by the liver. In this regard, caution should be exercised when prescribing antibiotics to patients with impaired liver function. Caution should be exercised when treating patients with moderate to severe renal failure with clarithromycin. In clinical practice, cases of toxicity of colchicine when combined with clarithromycin have been described, especially in elderly people. Some of them were observed in patients with renal failure; Several deaths have been reported in similar patients. The possibility of cross-resistance between clarithromycin and other macrolide drugs, as well as lincomycin and clindamycin, must be considered.
Application Klacid 250 mg 10 pcs. film-coated tablets during pregnancy and breastfeeding
The safety of clarithromycin in pregnant and lactating women has not been studied. Clarithromycin is known to be excreted in breast milk. Therefore, the use of clarithromycin during pregnancy and lactation is recommended only in cases where there is no safer alternative, and the risk associated with the disease itself outweighs the possible harm to the mother and fetus.
special instructions
In the presence of chronic liver diseases, it is necessary to regularly monitor serum enzymes.
Prescribe with caution against drugs metabolized by the liver.
In case of co-administration with warfarin or other indirect anticoagulants, PT must be monitored.
In children, it is preferable to use Klacid in powder dosage form for the preparation of an oral suspension of 125 mg/5 ml and 250 mg/5 ml.
Overdose
Symptoms: Taking a large dose of clarithromycin may cause symptoms of gastrointestinal disorders. In one patient with a history of bipolar disorder, changes in mental status, paranoid behavior, hypokalemia, and hypoxemia were described after taking 8 g of clarithromycin.
Treatment: in case of overdose, the unabsorbed drug should be removed from the gastrointestinal tract and symptomatic therapy should be carried out. Hemodialysis and peritoneal dialysis do not have a significant effect on clarithromycin serum levels, which is also typical for other macrolide drugs.
Side effects Klacid 250 mg 10 pcs. film-coated tablets
The most common adverse events were from the gastrointestinal tract, incl. diarrhea, vomiting, abdominal pain and nausea. Other adverse reactions included headache, taste disturbances, and transient increases in liver enzymes.
Post-marketing experience
During treatment with clarithromycin, liver dysfunction, including increased liver enzymes, and hepatocellular and/or cholestatic hepatitis, with or without jaundice, has been reported infrequently. Hepatic dysfunction can be severe and is usually reversible. In very rare cases, deaths from liver failure have been reported, which were usually observed in the presence of serious concomitant diseases and/or concomitant use of other drugs.
Isolated cases of increased serum creatinine levels have been described, but their connection with the drug has not been established.
Allergic reactions have been reported with oral administration of clarithromycin, ranging from urticaria and minor rashes to anaphylaxis and Stevens-Johnson syndrome/toxic epidermal necrolysis.
There have been reports of transient CNS effects including dizziness, anxiety, insomnia, nightmares, tinnitus, confusion, disorientation, hallucinations, psychosis and depersonalization; their cause-and-effect relationship with the drug has not been established.
Cases of hearing loss have been reported during treatment with clarithromycin; after cessation of treatment, hearing was usually restored. There are also cases of disturbances in the sense of smell, which are usually combined with a perversion of taste.
Glossitis, stomatitis, oral thrush and discoloration of the tongue have been described during treatment with clarithromycin. There are known cases of tooth discoloration in patients treated with clarithromycin. These changes are usually reversible and can be corrected by your dentist.
Rare cases of hypoglycemia have been described, some of which were observed in patients receiving oral hypoglycemic agents or insulin.
Isolated cases of leukopenia and thrombocytopenia have been reported.
When treating with clarithromycin, as with other macrolides, prolongation of the QT interval, ventricular tachycardia and torsade de pointes (TdP) have been observed in rare cases.
Rare cases of pancreatitis and seizures have been described.
There are reports of the development of interstitial nephritis during treatment with clarithromycin.
In clinical practice, cases of toxicity of colchicine when combined with clarithromycin have been described, especially in elderly people. Some of them were observed in patients with renal failure; Several deaths have been reported in similar patients.
Children with suppressed immune systems
In patients with AIDS and other immunodeficiencies receiving clarithromycin in higher doses over a long period of time for the treatment of mycobacterial infections, it is often difficult to differentiate the undesirable effects of the drug from symptoms of HIV infection or intercurrent illnesses.
The main adverse events in patients taking clarithromycin orally at a dose of 1 g were nausea, vomiting, taste disturbance, abdominal pain, diarrhea, rash, bloating, headache, hearing loss, constipation, increased AST and ALT levels. Dyspnea, insomnia, and dry mouth were also reported less frequently.
In this group of patients with suppressed immunity, significant deviations of laboratory parameters from normative values in specific tests (sharp increase or decrease) were recorded. Based on this, approximately 2–3% of patients taking clarithromycin orally at a dose of 1 g/day had significant laboratory abnormalities, such as increased AST, ALT levels and decreased white blood cell and platelet counts. Fewer patients also experienced elevated blood urea nitrogen levels.
Drug interactions
Interaction with cytochrome P450
Clarithromycin is metabolized in the liver by the cytochrome P4503A isoenzyme (CYP3A). This mechanism determines many interactions with other drugs. Clarithromycin may inhibit the biotransformation of other drugs by this system, which may lead to increased serum levels. The following drugs or classes are known or suspected to be metabolized by the same CYP3A isoenzyme: alprazolam, astemizole, carbamazepine, cilostazol, cisapride, cyclosporine, disopyramide, ergot alkaloids, lovastatin, methylprednisolone, midazolam, omeprazole, oral anticoagulants (e.g. warfarin), pimozide , quinidine, rifabutin, sildenafil, simvastatin, tacrolimus, terfenadine, triazolam and vinblastine. Similar mechanisms of interaction, which are mediated by other cytochrome P450 isoenzymes, are characteristic of phenytoin, theophylline and valproic acid. In clinical studies, there was a small but statistically significant (p) difference when combining theophylline or carbamazepine with clarithromycin.
In clinical practice, the following CYP3A-mediated interactions have been reported with the use of erythromycin and/or clarithromycin.
When clarithromycin was combined with HMG-CoA reductase inhibitors, such as lovastatin and simvastatin, rhabdomyolysis developed in rare cases.
With simultaneous use of clarithromycin with cisapride, an increase in the levels of the latter was observed. This may lead to prolongation of the QT interval and the development of cardiac arrhythmias, including ventricular tachycardia, ventricular fibrillation, and torsade de pointes (TdP). Similar effects have been reported in patients receiving clarithromycin with pimozide.
Macrolides caused disruption of the metabolism of terfenadine, which led to an increase in its plasma levels and was sometimes associated with the development of arrhythmias, incl. prolongation of the QT interval, ventricular tachycardia, ventricular fibrillation and torsade de pointes (TdP).
In one study of 14 healthy volunteers, the combined use of clarithromycin tablets and terfenadine resulted in a 2- to 3-fold increase in serum levels of the acid metabolite terfenadine and a prolongation of the QT interval, which was not associated with any clinical effects. In clinical practice, cases of ventricular tachycardia of the “pirouette” type have been reported when clarithromycin is combined with quinidine or disopyramide. Serum levels of these drugs should be monitored during treatment with clarithromycin.
Ergotamine/dihydroergotamine. In clinical practice, when clarithromycin was combined with ergotamine or dihydroergotamine, cases of acute toxicity of the latter, which is characterized by vasospasm and ischemia of the limbs and other tissues, including the central nervous system, were recorded.
Interaction with other drugs. In patients receiving clarithromycin tablets in combination with digoxin, an increase in serum concentrations of the latter was observed. Monitoring serum digoxin levels is advisable.
Colchicine. It is a substrate for CYP3A and P-glycoprotein. Clarithromycin and other macrolides are inhibitors of CYP3A and P-glycoprotein. When colchicine and clarithromycin are coadministered, inhibition of P-glycoprotein and/or CYP3A may result in increased effects of colchicine. Patients should be closely monitored for symptoms of colchicine toxicity.
Interaction with antiretroviral drugs. Concomitant oral administration of clarithromycin tablets with zidovudine in HIV-infected adults may result in a decrease in the Css of zidovudine. This interaction was not observed in HIV-infected children taking clarithromycin pediatric suspension with zidovudine or dideoxyinosine. In a pharmacokinetic study, the combined use of ritonavir at a dose of 200 mg every 8 hours and clarithromycin at a dose of 500 mg every 12 hours resulted in a significant suppression of the metabolism of clarithromycin. Cmax of clarithromycin when combined with ritonavir increased by 31%, Cmin by 182%, AUC by 77%.
Virtually complete inhibition of the formation of 14-hydroxyclarithromycin was observed. Given the high therapeutic index of clarithromycin, a dose reduction is not required in patients with normal renal function. However, in patients with impaired renal function, dose adjustment is advisable. In patients with Cl creatinine 30–60 ml/min, the dose of clarithromycin is reduced by 50%, and in patients with Cl creatinine