It is a synthetic nucleoside analogue active against HIV.

Lamivudine is a deoxy cytidine nucleoside analogue. It undergoes phosphorylation in the presence of Kinase enzyme and form Lamivudine triphosphate. This Lamivudine triphosphate competitively inhibit HIV reverse transcriptase enzyme which is responsible for the conversion of viral RNA to pro viral DNA and is then added to host cell chromosome. Lamivudine triphosphate   terminates elongation of pro viral DNA and results in inhibition of viral replication.  Lamivudine triphosphate is also a potent inhibitor of HBV (hepatitis B virus)

Pharmacokinetics
Absorption: It is rapidly absorbed after oral administration. Distribution: It is widely distributed in the body. Metabolism: Metabolism is insignificant. Excretion: It is excreted in urine.

Half Life
5 - 7 hours

Adverse Effects
1.Nausea
2.Vomiting
3.Diarrhoea
4.Anorexia
5.Headache
6.Dizziness
7.Anaemia
8.Neutropenia
9.Thrombocytopenia
10.Myalgia
11.Rash
12.Fever

ContraIndications
Hypersensitivity to Lamivudine

Special Precautions
1.Renal impairment
2.Hepatic dysfunction

Pregnancy
Use with caution

Breast Feeding
Contraindicated

Elderly
Use with caution

Children
Use with caution

Neonates
Contraindicated

Interactions
Trimethoprim, sulfamethoxazole: Results in an increase in AUC of Lamivudine and a decrease in renal clearance.
Zidovudine: Results in an increase in C max. of Zidovudine.

Indications
1.HIV infections
2.Treatment of chronic Hepatitis B

Dosage
Adult:
100 - 300 mg / day in 2 divided dose
HIV Infection: 300 mg / day in 2 divided dose
Treatment of chronic Hepatitis B: 100 mg / day

Children:
4 - 8 mg / kg /day in 2 divided dose
HIV infection: 4 mg / kg /day in 2 divided dose  
                     
Storage
Store it at 15 -25 degree C in a tightly closed container .Protect away from heat and light.

Missed Dose
Take the missed dose as soon as noticed and if it is the time to take the next dose then skip the missed dose and do not double the dose.

Over Dose
Give supportive measures and treatment.