From this article you will learn:
- what does Acyclovir help with?
- instructions for use of acyclovir (in children and adults),
- what analogues are there?
- tablets, ointment or cream acyclovir – price 2021.
Acyclovir is the first specific antiviral drug, which since 1981 has been widely used in the treatment of herpes simplex virus (types HSV-1, HSV-2), as well as herpes zoster and chickenpox. Type of virus HSV-1 - causes herpes on the lips, facial skin and oral mucosa. The HSV-2 virus type is predominantly genital herpes only, but in 10% of patients it can also cause both herpetic stomatitis and herpes labialis.
Acyclovir has a rather weak effect on other representatives of the herpevirus family (Epstein-Barr virus, cytomegalovirus). The drug is very well tolerated by children, even the youngest, and can also be used during pregnancy. Acyclovir cream or ointment is intended for external use and is available without a prescription, but Acyclovir tablets or vials for intravenous administration should be used only as prescribed by a doctor!
Acyclovir: photos of several release options
Composition and release form –
- cream for external use 5%,
- ointment for external use 5%,
- eye ointment 3%,
- Acyclovir tablets 200 and 400 mg,
- in bottles for preparing a solution (200 mg, 250 mg, 500 mg or 1 g).
Acyclovir analogues of the drug - the original drugs of acyclovir are drugs from the Zovirax line - from (Great Britain). All drugs containing acyclovir from other manufacturers are only generics, for example, Acyclovir-Akrikhin (Russia), Acyclovir-Sandoz (Switzerland), Acyclovir-Hexal (Germany), Acyclovir-Belupo (Croatia), as well as many others. And although manufacturers of generic drugs say that their drugs are no less effective, most doctors believe that generic drugs are still inferior to original drugs in terms of such criteria as effectiveness and safety. At the end of the article, you can also read about modern analogues of acyclovir - the antiviral drugs Famciclovir, Valacyclovir and Penciclovir.
Important: the original acyclovir under the Zovirax brand in tablets can be taken from 0 years of age. At the same time, the instructions for the Russian drug “Acyclovir-Akrikhin” indicate that children under 2 years of age are a contraindication. The same applies to the use of Acyclovir tablets during breastfeeding (Zovirax is allowed with caution, but for the Russian analogue this would be a contraindication).
Description:
Round flat-cylindrical tablets of white or almost white color with a chamfer and a score.
Pharmacological group:
antiviral agent.
ATX code:
J05AB01
pharmachologic effect
Pharmacological properties
Pharmacodynamics
Mechanism of action
Acyclovir
is a synthetic analogue of a purine nucleoside that has the ability to inhibit in vitro and in vivo human herpes viruses, including herpes simplex virus (HSV) types 1 and 2, varicella zoster virus and herpes zoster virus (Varicella zoster virus (Varicella zoster virus). VZV), Epstein-Barr virus (EBV) and cytomegalovirus (CMV). In cell culture, acyclovir has the most pronounced antiviral activity against HSV-1, followed in descending order of activity by HSV-2, VZV, EBV and CMV.
The inhibitory effect of acyclovir on herpes viruses (HSV-1, HSV-2, VZV, EBV and CMV) is highly selective. Acyclovir is not a substrate for the thymidine kinase enzyme in uninfected cells, therefore acyclovir is of low toxicity to mammalian cells. However, thymidine kinase of cells infected with HSV, VZV, EBV and CMV viruses converts acyclovir into acyclovir monophosphate, a nucleoside analogue, which is then sequentially converted into diphosphate and triphosphate under the action of cellular enzymes. The incorporation of acyclovir triphosphate into the viral DNA chain and subsequent chain termination blocks further replication of the viral DNA.
In patients with severe immunodeficiency, long-term or repeated courses of acyclovir therapy may lead to the emergence of resistant strains, so further treatment with acyclovir may be ineffective. Most isolated strains with reduced sensitivity to acyclovir had a relatively low content of thymidine kinase, as well as a disorder in the structure of the viral thymidine kinase or DNA polymerase. In vitro exposure of herpes simplex virus (HSV) strains to acyclovir may also result in the formation of strains that are less sensitive to it. A correlation has not been established between the sensitivity of herpes simplex virus (HSV) strains to acyclovir in vitro and the clinical effectiveness of the drug.
Pharmacokinetics
Suction
Acyclovir is only partially absorbed from the intestine. After taking 200 mg of acyclovir every 4 hours, the mean maximum steady-state plasma concentration (Cssmax) was 3.1 μM (0.7 μg/ml), and the mean steady-state minimum plasma concentration (Cssmin) was 1.8 μM (0 .4 µg/ml). When administered orally 400 mg and 800 mg of acyclovir every 4 hours, Cssmax was 5.3 µM (1.2 µg/ml) and 8 µM (1.8 µg/ml), respectively, and Cssmin was 2.7 µM (0.6 µg /ml) and 4 µM (0.9 µg/ml), respectively.
Distribution
The concentration of acyclovir in the cerebrospinal fluid is approximately 50% of its concentration in blood plasma.
Acyclovir binds to blood plasma proteins to an insignificant extent (9-33%), so drug interactions due to displacement from binding sites with blood plasma proteins are unlikely.
Removal
In adults, after taking acyclovir orally, the half-life from blood plasma is about 3 hours. Most of the drug is excreted unchanged by the kidneys. The renal clearance of acyclovir significantly exceeds the clearance of creatinine, which indicates that acyclovir is eliminated through not only glomerular filtration, but also tubular secretion. 9-carboxymethoxy-methylguanine is the main metabolite of acyclovir and accounts for about 10-15% of the dose excreted in the urine. When acyclovir was administered 1 hour after taking 1 g of probenecid, the half-life of acyclovir and AUC (area under the concentration-time pharmacokinetic curve) increased by 18 and 40%, respectively.
History of the creation of Acyclovir, interesting facts
The drug was synthesized in the early 70s of the last century by an employee of the laboratory of one of the largest pharmaceutical companies today - GlaxoSmithKline (although it was called differently then). The name of this discoverer of Acyclovir is Howard Schaeffer .
However, the world learned about entering a new era in the treatment of viral diseases from another employee of the same laboratory - Miss G. Elion . This intelligent and courageous woman received the Nobel Prize in Physiology or Medicine in 1988 . However, by education she was neither a doctor nor a physiologist. But this woman scientist realized her desire to help people in the fight against disease after the death of her grandfather from cancer, which she told the public about in her Nobel speech.
The synthesis of Acyclovir was preceded by the preparation of 2,6-diaminopurine. This substance did not live up to expectations, as it turned out to be toxic to humans. However, the creators of Acyclovir continued to synthesize diaminopurine derivatives. And, oh, Eureka, acycloguanosine has shown high effectiveness. However, this derivative was not toxic in comparison with its progenitor. This substance was later named Acyclovir.
To synthesize Acyclovir, it was necessary to obtain nucleosides. For this purpose, a Caribbean sponge living in the sea of the same name was used. So, in part, Acyclovir can be considered a medicine of natural origin. Nucleosides have also been obtained from Tectitethya Crypta to create an anticancer drug.
For several years the new medicine was kept secret. It was not until 1982 that the drug was approved by the Food and Drug Administration in the United States and marketed under the trade name Zovirax.
Indications for use
— Treatment of infections of the skin and mucous membranes caused by the herpes simplex virus, including primary and recurrent genital herpes;
- prevention of relapses of infections caused by the herpes simplex virus in patients with normal immune status;
- prevention of infections caused by the herpes simplex virus in patients with immunodeficiency;
- treatment of chickenpox and herpes zoster (early treatment of herpes zoster with acyclovir has an analgesic effect and can reduce the incidence of postherpetic neuralgia).
Use during pregnancy and lactation.
Fertility
There is no data on the effect of acyclovir on female fertility.
A study of 20 male patients with normal sperm counts found that oral acyclovir up to 1 g per day for 6 months had no clinically significant effect on sperm count, motility or morphology.
Pregnancy
The post-registration registry of pregnancies during treatment with acyclovir collected data on pregnancy outcomes in women taking acyclovir in different dosage forms. In an analysis of registry data, there was no increase in the number of birth defects in infants whose mothers took acyclovir during pregnancy compared with the general population. The identified birth defects were not uniform or consistent, suggesting a common cause.
However, caution should be exercised when prescribing Acyclovir to women during pregnancy and assess the expected benefit to the mother and the possible risk to the fetus.
Breastfeeding period
After taking the drug Acyclovir orally at a dose of 200 mg 5 times a day, acyclovir was determined in breast milk at a concentration ranging from 60 to 410% of the plasma concentration. At such concentrations in breast milk, breastfed infants can receive acyclovir in doses up to 0.3 mg/kg/day. Given this, caution should be exercised when prescribing Acyclovir to nursing women.
Acyclovir: price for 2021
The price of the drug acyclovir in 2021 has not increased compared to previous years, which is most likely due to high competition between manufacturers, as well as the appearance in pharmacies of a large number of more modern and effective analogues of acyclovir. The highest price is the original Acyclovir from GlaxoSmithKline (UK), sold under the Zovirax brand.
Ointment and cream Acyclovir 5% –
- Acyclovir-Acri ointment, 5 g – from 35 rubles,
- Acyclovir-Belupo cream, 5 g – from 70 rubles,
- Acyclovir-Sandoz cream, 5 g – from 150 rubles (2 g tube – from 75 rubles),
- Zovirax cream, 5 g – from 190 rub.
- Zovirax Duo-Active cream, 2 g – from 350 to 400 rubles.
Please note that all of the above products contain propylene glycol (to enhance the penetration of acyclovir into tissues). However, despite this, the ointment will in any case be inferior in effectiveness to the cream. The second point is that only Acyclovir-Sandoz cream and both Zovirax creams contain dimethicone, which will allow you to easily apply cosmetics over the absorbed cream.
Eye ointment Acyclovir 3% –
- Acyclovir-Sintez (Russia) – from 150 rubles,
- Acyclovir-Akos (Russia) – from 150 rubles,
- Zovirax 3% (UK) – from 240 rubles.
Acyclovir tablets: price
- Zovirax 200 mg (25 tablets) – from 250 rubles,
- Acyclovir Acri 200 mg (20 tablets) – from 70 rubles,
- Acyclovir Acri 400 mg (20 tablets) – from 220 rubles.
Directions for use and doses
Acyclovir tablets can be taken with meals, since food intake does not significantly interfere with its absorption. The tablets should be taken with a full glass of water.
Adults
Treatment of skin and mucous membrane infections caused by the herpes simplex virus, including primary recurrent genital herpes
For the treatment of infections caused by the herpes simplex virus, the recommended dose of Acyclovir is 200 mg orally 5 times a day (every 4 hours, except during nighttime sleep). The course of treatment is 5 days, but can be extended for severe primary infections.
In case of severe immunodeficiency (for example, after bone marrow transplantation) or in case of impaired absorption from the intestine, the dose of Acyclovir can be increased to 400 mg. As an alternative, the possibility of using acyclovir in a lyophilisate dosage form for the preparation of a solution for infusion may be considered.
Treatment should begin as soon as possible after infection occurs; in case of relapses, it is recommended to prescribe the drug already in the prodromal period or the appearance of the first elements of the rash.
Prevention of recurrent infections caused by the herpes simplex virus in patients with normal immune status
To prevent recurrence of infections caused by the herpes simplex virus in patients with normal immune status, the recommended dose of Acyclovir is 200 mg orally 4 times a day (every 6 hours).
Many patients benefit from a more convenient treatment regimen of 400 mg orally 2 times a day (every 12 hours).
In some cases, lower doses of Acyclovir are effective: 200 mg orally 3 times a day (every 8 hours) or 200 mg orally 2 times a day (every 12 hours).
Some patients may experience exacerbation of infection when taking a total daily dose of 800 mg.
Treatment with Acyclovir should be interrupted every 6-12 months to identify possible changes in the course of the disease.
Prevention of infections caused by herpes simplex virus in patients with immunodeficiency
For the prevention of infections caused by the herpes simplex virus in patients with immunodeficiency, the recommended dose of Acyclovir is 200 mg orally 4 times a day (every 6 hours).
In case of severe immunodeficiency (for example, after bone marrow transplantation) or in case of impaired absorption from the intestine, the dose of the drug can be increased to 400 mg orally. As an alternative, the possibility of using acyclovir in a lyophilisate dosage form for the preparation of a solution for infusion may be considered.
The duration of the prophylactic course of therapy is determined by the length of the period during which there is a risk of infection.
Treatment of chickenpox and herpes zoster
For the treatment of chickenpox and herpes zoster, the recommended dose of Acyclovir is 800 mg orally 5 times a day (every 4 hours, except during night sleep). The course of treatment is 7 days.
Treatment of herpes zoster should begin as early as possible from the moment of the first manifestations of the disease, since in this case the treatment will be more effective.
Treatment of chickenpox in patients with normal immune status should begin within 24 hours of the onset of the rash.
In patients with severe immunodeficiency (for example, after bone marrow transplantation) or in cases of impaired absorption from the intestine, it is necessary to consider the possibility of prescribing acyclovir in a lyophilisate dosage form for the preparation of a solution for infusion.
Special patient groups
Children aged 3 years and older
Treatment of infections caused by the herpes simplex virus; prevention of infections caused by the herpes simplex virus in patients with immunodeficiency
- aged 3 years and older - the same doses as for adults.
Treatment of chickenpox
- aged 6 years and older - 800 mg orally 4 times a day;
- aged 3 to 6 years - 400 mg orally 4 times a day.
More precisely, the dose can be determined at the rate of 20 mg/kg body weight (but not more than 800 mg) orally 4 times a day. The course of treatment is 5 days.
Prevention of recurrence of infections caused by the herpes simplex virus in patients with normal immune status; treatment of herpes zoster
There are no data on dosage regimen.
Elderly patients
The likelihood of renal failure in elderly patients must be taken into account, and doses should be adjusted according to the degree of renal failure (see subsection "Patients with impaired renal function").
It is necessary to ensure that adequate water balance is maintained.
Patients with impaired renal function
Caution must be exercised when prescribing Acyclovir to patients with impaired renal function.
It is necessary to ensure that adequate water balance is maintained.
In patients with renal failure, oral administration of acyclovir at recommended doses for the treatment and prevention of infections caused by the herpes simplex virus does not lead to accumulation of the drug to concentrations exceeding established safe levels. However, in patients with creatinine clearance less than 10 ml/min, the dose of Acyclovir is recommended to be reduced to 200 mg orally 2 times a day (every 12 hours).
For the treatment of chickenpox and herpes zoster, the recommended doses of Acyclovir tablets are:
— with creatinine clearance less than 10 ml/min—800 mg orally 2 times a day (every 12 hours);
- with creatinine clearance 10-25 ml/min - 800 mg orally 3 times a day (every 8 hours).
Ingredients: per capsule
Active ingredients: alpha-glutamyl-tryptophan sodium (Timogen® sodium) 0.5 mg, ascorbic acid 50 mg, bendazole hydrochloride (Dibazol) 20 mg; Excipients: Lactose monohydrate 97.8 mg, calcium stearate 1.7 mg;
Composition of the capsule shell:
Body: titanium dioxide 2%, gelatin up to 100%. Cap: titanium dioxide 2%, sunset yellow dye 0.2190%, azorubine dye 0.0328, gelatin up to 100%.
Description:
Hard gelatin capsules No. 3 with a white body and an orange cap. The contents of the capsules are odorless, white to yellow powder.
Pharmacotherapeutic group:
Immunostimulating agent.
ATX code: L03AX
Pharmachologic effect:
Pharmacodynamics:
The drug is a means of etiotropic and immunostimulating therapy, has an indirect antiviral effect against influenza A and B pathogens, as well as other viruses that cause acute respiratory diseases.
In in vitro studies, the drug specifically suppresses (inhibits) the reproduction (replication) of the SARS-CoV-2 virus, which is the causative agent of the new coronavirus infection (COVID-19).
The degree of inhibition of the pathogen increases with increasing concentration of the drug (the linearity of the dose-effect relationship is shown). Reduces the severity of the main clinical symptoms of influenza and ARVI, and also shortens the duration of the disease and contributes to its uncomplicated course.
Increases the content of secretory immunoglobulin A (slgA) in the mucous membrane of the nasopharynx - the entrance gate of infection, increasing the local immunoresistance of the body to respiratory infections of a viral and bacterial nature.
With a preventive effect, the drug increases the potential metabolic activity of innate immune cells (neutrophil granulocytes and monocytes), which, in the event of infection, increases their ability to absorb and destroy bacterial and viral agents due to increased enzymatic (oxidative) activity, synthesis of cationic proteins and increased number of phagocytic cells. In this case, the initial state of metabolic activity of innate immune cells, in the absence of infectious agents, does not change, being within normal values.
Bendazole induces the body's production of endogenous interferon and has an immunomodulatory effect (normalizes the body's immune response to various infectious agents). Enzymes, the production of which is induced by interferon in the cells of various organs, inhibit viral replication.
Alpha-glutamyl-tryptophan (thymogen) is a synergist for the immunomodulatory effect of bendazole, normalizing the T-cell component of immunity.
Ascorbic acid activates the humoral component of the immune system, normalizes capillary permeability, thereby reducing inflammation, exhibits antioxidant properties, neutralizing oxygen radicals that accompany the inflammatory process, and increases the body's resistance to infection.
Pharmacokinetics:
When taken orally, the drug is completely absorbed from the gastrointestinal tract. The bioavailability of bendazole is about 80%, alpha-glutamyl tryptophan is no more than 15% and ascorbic acid is 90%. Metabolites of ascorbic acid and bendazole are excreted in the urine. Alpha-glutamyl-tryptophan, under the influence of peptidases, is broken down into L-glutamic acid and L-tryptophan, which are used by the body in peptide synthesis.
Indications for use:
Prevention and complex therapy of influenza and acute respiratory viral infections in adults and children over 6 years of age.
Contraindications:
Hypersensitivity to the components of the drug, pregnancy, children under 6 years of age.
Carefully:
during breastfeeding, use is possible if the expected benefit to the mother outweighs the potential risk to the child.
Directions for use and dosage:
Inside, 30 minutes before meals. Single dose for adults and children over 6 years of age – 1 capsule. For treatment: one capsule 3 times a day for 4 days. For prevention: - in direct contact with a patient with influenza and other acute respiratory viral infections, one capsule 3 times a day for 4 days. — during the period of epidemic rise in the incidence of influenza and other acute respiratory viral infections, one capsule 1 time per day for 12 days. Preventive courses, if necessary, are repeated after 3 weeks (until the epidemic situation normalizes).
Side effects:
Allergic reactions, short-term decrease in blood pressure.
Overdose:
Symptoms: short-term decrease in blood pressure in elderly patients with vegetative-vascular dystonia. Monitoring of kidney function, blood pressure and blood glucose concentrations is necessary.
Interaction with other drugs:
No interaction of alpha-glutamyl-tryptophan with drugs has been identified.
Bendazole prevents the increase in total peripheral vascular resistance caused by the use of non-selective beta-blockers. Strengthens the hypotensive (lowering blood pressure) effect of antihypertensive and diuretic drugs. Phentolamine enhances the hypotensive effect of bendazole.
Ascorbic acid increases the concentration in the blood of antibacterial drugs of the tetracycline series and benzylpenicillin. Improves the absorption of iron (Fe) preparations in the intestines. Reduces the effectiveness of heparin and indirect anticoagulants. Acetylsalicylic acid (ASA), oral contraceptives, fresh juices and alkaline drinks reduce its absorption and absorption. When used simultaneously with ASA, the urinary excretion of ascorbic acid increases and the excretion of ASA decreases. ASA reduces the absorption of ascorbic acid by approximately 30%. Ascorbic acid increases the risk of developing crystalluria when using drugs containing acetylsalicylic acid (ASA) and short-acting sulfonamides, slows down the excretion of acids by the kidneys, increases the excretion of drugs that have an alkaline reaction (including alkaloids), and reduces the concentration in the blood of oral contraceptives. When used simultaneously, it reduces the chronotropic effect of isoprenaline. Reduces the therapeutic effect of antipsychotic drugs (neuroleptics) - phenothiazine derivatives, tubular reabsorption of amphetamine and tricyclic antidepressants. Barbiturates and primidone increase the excretion of ascorbic acid in the urine.
Possible simultaneous use with antiviral drugs and symptomatic treatment of influenza and ARVI.
Consult your doctor if you are taking the medications listed in this section or other medications.
Special instructions:
The drug does not affect the ability to drive vehicles or engage in other potentially hazardous activities that require increased concentration and speed of psychomotor reactions.
Release form:
Capsules. 12 capsules each in a blister pack made of PVC/PCTFE/PVC film (polyvinyl chloride/polychlorotrifluoroethylene/polyvinyl chloride) or PVC/PVDC/PVC (polyvinyl chloride/polyvinylidene chloride/polyvinyl chloride) and printed varnished aluminum foil. One, or two, or four blister packs with instructions for use in a cardboard pack.
Storage conditions:
At a temperature not higher than 25 oC. Keep out of the reach of children.
Best before date:
3 years. Do not use after the expiration date stated on the packaging.
Vacation conditions:
Over the counter.
Legal entity in whose name the registration certificate was issued: Joint Stock Company Medical-Biological Research and Production Complex Cytomed, Russia. (Cytomed Oy). Production site address: Finland, 55300 Rauha, Laastitie 1 Cytomed Oy. Finland, 55300 Rauha, Laastitie 1. Name and address of the organization authorized by the holder (owner) of the registration certificate of a medicinal product for medical use to accept claims from the consumer: JSC MBNPC Cytomed, Russia. 194356, St. Petersburg, Orlovo-Denisovsky prospect, 14, building 1, tel., cytomed.ru.
Side effect
The frequency categories of adverse reactions listed below are estimates. For most adverse reactions, the necessary data to determine the frequency of occurrence are not available. In addition, the incidence of adverse reactions may vary depending on the indication.
The adverse reactions presented below are listed according to their frequency of occurrence, defined as follows: very common (>1/10), common (>1/100 and <1/10), uncommon (>1/1000 and <1/100 ), rare (>1/10,000 and <1/1000), very rare (<1/10,000).
Frequency of occurrence of adverse reactions
Blood and lymphatic system disorders
Very rare: anemia, leukopenia, thrombocytopenia.
Immune system disorders
Rarely: anaphylaxis.
Nervous system and mental status disorders
Common: headache, dizziness.
Very rare: agitation, confusion, tremor, ataxia, dysarthria, hallucinations, psychotic symptoms, convulsions, drowsiness, encephalopathy, coma.
Typically, these side effects were observed in patients with renal failure or in the presence of other precipitating factors and were mainly reversible (see section "Special instructions"
).
Respiratory, thoracic and mediastinal disorders
Rarely: shortness of breath.
Gastrointestinal disorders
Common: nausea, vomiting, diarrhea, abdominal pain.
Disorders of the liver and biliary tract
Rare: reversible increase in the concentration of bilirubin and liver enzymes in the blood.
Very rare: hepatitis, jaundice.
Skin and subcutaneous tissue disorders
Common: itching, rash, including photosensitivity.
Uncommon: urticaria, rapid diffuse hair loss.
Since rapid diffuse hair loss is observed in various diseases and during therapy with many drugs, its connection with the use of acyclovir has not been established.
Rarely: angioedema.
Very rare: toxic epidermal necrolysis, exudative erythema multiforme.
Renal and urinary tract disorders
Rarely: increased concentrations of urea and creatinine in the blood serum.
Very rare: acute renal failure, renal colic.
Renal colic may be associated with renal failure and crystalluria.
General and administration site disorders
Common: fatigue, fever.
Purchasing Acyclovir at a pharmacy. Home storage
The drug in the form of tablets, suspension, lyophilisate must be prescribed exclusively by a doctor and is dispensed from a pharmacy upon presentation of a prescription. External lekforms are freely available.
Storage conditions for Acyclovir-based drugs vary depending on the manufacturer. The vast majority can be left in the closet at home. However, there are exceptions, for example, 5% Acyclovir ointment from Sintez OJSC (Kurgan, Russia). This medication should be stored in the refrigerator. Do not put external preparations with the above-mentioned active ingredient in the freezer.
Overdose
Acyclovir is only partially absorbed from the gastrointestinal tract. As a rule, no toxic effects have been reported with a random single dose of acyclovir up to 20 g. With repeated oral doses over several days of doses exceeding the recommended ones, disturbances from the gastrointestinal tract (nausea, vomiting) and nervous system (headache and confusion) were observed. Sometimes neurological effects such as seizures and coma may occur.
Patients require careful medical monitoring to identify possible symptoms of intoxication. Acyclovir is eliminated from the body by hemodialysis, so hemodialysis can be used to treat overdose.
Contraindications
The drug has no absolute contraindications. However, you should prescribe and use Acyclovir with caution when:
- pregnancy;
- breastfeeding;
- kidney disorders;
- reaching old age;
- severe dehydration due to taking large doses of the drug;
- history of neurological disorders or reactions to the use of cytotoxic drugs.
Each dosage form has its own age-related contraindications. For example, it is not recommended to prescribe tablets to children under three years of age due to the fact that they will not be able to swallow them and will choke. Ointments and creams based on Acyclovir are not applied to children under 2 years of age, as they can lick off the medicine, wipe it off, and also because the permeability of the skin at such a tender age is increased, which means systemic effects are possible.
Photo: https://pixabay.com/photos/pregnant-mother-body-pregnant-woman-1245703/