| Acyclovir Pharmacology |
| Acyclovir |
| About Acyclovir |
| Synthetic purine nucleoside, it is an antiviral drug. |
| Mechanism of Action of Acyclovir |
| Acyclovir is converted to Acyclovir monophosphate by Thymidine kinase and it is again phosphorylated by Cellular kinase. This Acyclovir triphosphate competitively inhibits DNA polymerase enzyme and inhibits DNA synthesis. Acyclovir triphosphate is also incorporated in viral DNA and stops the DNA elongation and permanent inactivation. |
| Pharmacokinets of Acyclovir |
| Absorption: Acyclovir is incompletely absorbed after oral administration. Distribution: It is widely distributed in the body. Metabolism: It undergoes metabolism in the viral cell to active metabolite. Excretion: It is excreted through urine |
| Onset of Action for Acyclovir |
| With in a day |
| Duration of Action for Acyclovir |
| 8 hours |
| Half Life of Acyclovir |
| 2 – 3 hour |
| Side Effects of Acyclovir |
| 1.Nausea 2.Vomiting 3.Burning 4.Stinging 5.Tremor 6.Hallucinations 7.Lethargy 8.Phlebitis 9.Malaise |
| Contra-indications of Acyclovir |
| Hypersensitivity to Acyclovir |
| Special Precautions while taking Acyclovir |
| 1.Renal impairment 2.Psychiatric problems 3.Depression 4.Patients taking nephrotoxic drugs |
| Pregnancy Related Information |
| Use with caution |
| Old Age Related Information |
| Use with caution. |
| Breast Feeding Related Information |
| Use with caution. |
| Children Related Information |
| May be used NEONATES: use with caution |
| Indications for Acyclovir |
| 1.Herpes simplex virus infection 2.Herpes zoster infections 3.Chicken pox |
| Interactions for Acyclovir |
| Probenecid: Increases efficacy by decreasing urinary excretion and increasing half-life. Zidovudine: Causes severe drowsiness and lethargy. |
| Typical Dosage for Acyclovir |
| Adult: Herpes zoster infection: 1 – 4 g / day in 5 divided doses (take every 4 hour while awake) for 7 – 10 days dose is depend upon the severity, duration and type of infection HSV in immunocompromised patient: 1 – 4 g / day in 5 divided doses (take every 4 hour while awake): dose is depend upon the severity, duration and type of infection Genital herpes: 1g / day in 5 divided dose (take every 4 hour while awake) for 10 days Genital herpes in immunocompromised patient: 1 – 2 g / day in 3 – 5 divided dose Chicken pox: 3. 2g / day in 4 divided dose for 5 days Herpes zoster ophthalmicus: 3 g / day in 5 divided dose (take every 4 hour while awake) for 10 days Children: Herpes zoster / Herpes simplex: 15 mg / kg body weight / day in 3 divided dose Chicken pox: 80 mg / kg body weight / day in 4 divided dose for 5 days |
| Schedule of Acyclovir |
| H |
| Storage Requirements for Acyclovir |
| Store in airtight container at a temperature of 15 – 25 degree C.Protect from heat and light. Keep out of the reach of children. |
| Effects of Missed Dosage of Acyclovir |
| Take the missed dose as soon as noticed and if it is the time to next dose then skip the missed dose. |
| Effects of Overdose of Acyclovir |
| Give supportive and symptomatic treatment. |