1 g of cream contains: Pharmacologically active ingredient: Acyclovir 50 mg.
Acyclovir Stada is an anti-viral drug.
Excipients/Inactive Ingredients: Dimethicone, PEG-5-glycerol-stearate, cetyl alcohol, liquid paraffin, propylene glycol, white vaseline, purified water.
Pharmacology: Mode of Action: Acyclovir is a guanine derivative whose activity is essentially confined to viral thymidine kinase-producing human pathogenic herpes viruses, i.e. herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), and varicella-zoster virus (VZV). Acyclovir is not pharmacologically active until it has been converted by viral thymidine kinase inside virally infected cells along the following pathway: Phosphorylation of acyclovir (the substrate) to acyclovir monophosphate is faster by viral thymidine kinase than by host cell thymidine kinase. The relative selectivity minimizes the toxicity of acyclovir to host cells. Normal cellular nucleotidyl phosphotransferases then catalyse the sequential conversion of acyclovir monophosphate to acyclovir triphosphate.
Acyclovir triphosphate (the active form of the drug) selectively inhibits viral DNA polymerase and is incorporated into viral DNA. Acyclovir triphosphate competitively displaces deoxyguanosine triphosphate from DNA polymerases. Acyclovir triphosphate has higher affinity for HSV-encoded DNA polymerase than cellular DNA polymerase (10 to 20 times greater). It acts as a substrate for HSV-encoded DNA polymerase and, cleaving off diphosphate is incorporated into viral DNA. However, as acyclovir lacks a 3-hydroxyl group, nucleotides can no longer be added by 3',5'-linkage, causing chain termination. Moreover, the DNA-viral polymerase complex remain intact, inactivating the enzyme. Acyclovir activity is greatest against HSV-1 and HSV-2 because these depend on their own thymidine kinase for replication. Acyclovir is also a substrate for VZV-encoded thymidine kinase, but the concentrations required for anti-VZV activity are higher. Acyclovir also inhibits EBV DNA polymerase. Toxicity to the host cell is low because of the drug's high affinity for viral enzymes. Acyclovir is also active against the Epstein-Barr virus (EBV), cytomegalovirus (CMV) and other herpes viruses (varicella-like simian virus, DHV 1, neurotropic and tumour viruses pseudorabies virus, PDV), but to a lesser extent and may act via a different mechanism of action.
Pharmacokinetics: Absorption: Percutaneous drug absorption from topical dosage forms depends on the ability of the drug (active ingredient) to penetrate the skin as well as on the vehicle.
An in-vitro study on the penetration capacity of acyclovir using PEG (polypropylene glycol) modified aqueous base and DMSO (dimethyl sulphoxide) demonstrated an increase of 8- and 60 fold-fold increase in the release of acyclovir from the modified aqueous vehicle and DMSO compared to PEG ointment. The composition of Acyclovir Stada Cream is essentially identical with the composition of hydrophilic [poly] propylene glycol-based acyclovir cream, but it was improved by using substances with a lower potential for skin irritancy, while maintaining the dermal penetration profile of the former formulation. Hence, the vehicle formulation used in Acyclovir Stada Cream shows good percutaneous absorption.
Bioavailability: Systemic absorption of topical acyclovir is minimal and the resulting blood levels are below the limit of detection. It is therefore impossible to characterize the kinetics of bioavailability of topical acyclovir. Toxic effects are unlikely with topical acyclovir because the drug does not reach the systemic circulation.
Treatment of herpes simplex virus infection of the skin including initial and recurrent genital herpes and herpes labialis.
The instructions given as follows apply unless the doctor has prescribed Acyclovir Stada otherwise. Please comply with these and/or the doctor's instructions for effective and safe Acyclovir Stada therapy.
How much and how often should the patient use Acyclovir Stada: Apply a thin film of cream to infected skin areas 5 times daily every 4 hours.
How and when should the patient use Acyclovir Stada: Use a cotton swab to take up as much cream as is necessary to cover the infected skin area(s). As the patient applies Acyclovir Stada, be sure to cover not only the areas with visible signs of herpes infection (vesicles, swelling, reddening) but adjacent areas as well. Should the patient be applying Acyclovir Stada with hand(s), be sure to wash these thoroughly both before and after cream application to prevent additional infection of the compromised skin area(s) (with bacteria etc.) and/or viral carry over to other, as yet uninfected mucosal or skin areas.
Please note: For best response, Acyclovir Stada therapy should be started as early as possible, i.e. as soon as the patient notices the first signs of herpes (burning, itching, discomfort, reddening).
For how long should the patient use Acyclovir Stada: The doctor will determine how long the patient should continue Acyclovir Stada therapy. Treatment is usually continued for 5 days but therapy should be individualized and continued until vesicular crusting or healing has been achieved. However, the duration of therapy should not exceed 10 days.
Violations of dosing schedule and overdosage action: What should the patient do if he/she used less than the prescribed dose of Acyclovir Stada or missed dose: Continue therapy as prescribed (so do not apply the cream more often and do not apply a thicker film or cream).
What should the patient bear in mind if he/she wishes to interrupt or stop Acyclovir Stada early: The patient should use Acyclovir Stada sufficiently long to ensure best results.
When should the patient not use Acyclovir Stada: The patient must not use Acyclovir Stada if the patient is hypersensitive to acyclovir or any other ingredient of Acyclovir Stada. The patient should not apply Acyclovir Stada to mucous membranes (e.g. oral cavity, eye or vagina) to avoid local irritation.
When should the patient use Acyclovir Stada - only after checking with the doctor: The situations described here relate to certain conditions in which Acyclovir Stada should be used only with particular caution. Discuss with the doctor, also if any of these conditions applied to the patient previously. Be sure to inform the doctor before starting therapy if the patient is severely immunocompromised (i.e. if the body's immune system is severely impaired).
When using Acyclovir Stada in the genital or anal region and a latex condom at the same time, the condom's resistance to tear may be reduced by the paraffin and petroleum jelly contained in Acyclovir Stada, compromising condom reliability.
No information is available on the effects of administration of Acyclovir cream during human pregnancy.
What adverse reactions could the patient experience while using Acyclovir Stada: Should the patient experience any adverse effects not described in this monograph, be sure to inform a doctor or pharmacist. Application of Acyclovir Stada may produce transient burning or stinging of the treated skin areas. Reddening, drying and scaling of Acyclovir Stada - treated skin have occasionally been observed.
There have been rare reports of allergic skin reactions (contact dermatitis) following the use of Acyclovir Stada. In most cases where allergological testing was performed, the pharmaceutical aids of the cream base rather than the active ingredient Acyclovir proved the cause of the skin reaction. The patient may be suffering from contact dermatitis if the previously mentioned side effects are pronounced and involve also skin areas beyond those treated with the cream. Discuss with a doctor.
What other medicines are known to interfere with the effects of Acyclovir Stada or are themselves affected by Acyclovir Stada: No interactions with other drugs are known to date.
Store Acyclovir Stada at maximum 25°C.
D06BB03 - aciclovir ; Belongs to the class of topical antivirals used in the treatment of dermatological diseases.
Cream 2 g:P+, POM;Cream 5 g:POM
Cream 5% (white to off-white homogenous) x 2 g, 5 g.