Trade name : Ritomune
Active ingredient : Ritonavir
Strength availability : 100mg
Manufactured by : Cipla
Package : 60 tablets in a container
Category : Anti-retroviral drug
Ritonavir is sold under the brand name of Ritomune tablets and it anti-retroviral drug. Ritomune is also a CYP3A inhibitor Ritomune is classified as HIV protease inhibitor drug, which is peptidomimetic agent containing both HIV-1 & HIV-2 protease inhibitor activity. Ritomune is exhibits anti-retroviral activity by interceding with reproductive cycles of HIV.
Ritomune tablets are widely indicated for treating HIV-1 infection by combining with other anti-retroviral medications.
MECHANISM OF ACTION
HIV protease enzymes which is involves in separation of structural & multiplicative proteins that may produce from major HIV genes, like gag & pol. This activity of enzyme should be reduced due to inhibiting the protease enzyme by ritonavir, an active substance of Ritomune tablets. Gal: conceal the proteins complicated in core & nucleocapsid. Pol: conceal the reverse transcriptase, ribonuclease H, integrase & protease. The separation of gal-pal polyprotein should be prevented by ritonavir which leads to production of immature and non infectious viral particles.
The prescribed doses of Ritomune for adults are; 600mg should be administered orally as two times a day. Ritomune tablets should be initiated by not less than 300mg as two times a day followed by increased dose at 2 to 3 days by 100mg as twice daily. The maximum dose is 600mg and it should not be exceeded. For pediatric; Ritomune should be used by combining with other antiretroviral drugs. The prescribed dose of Ritomune is 350 to 400mg/m2 as two times a day for pediatric patients with age of older than 1 month. The dose should not be exceeded to 600mg The initial dose of Ritomune is 250mg/m2 two times day and increased at 2 to 3 days interal by 50mg/m2 as two times a day. Depending on body surface area, the dose should be calculated. Dose reduction is required when Ritomune is combined with atazanavir, darunavir, fosamprenavir, saquinavir & tipranavir.
The maximum plasma concentration time of ritonavir after the dose administration, causes within 2 hours & 4 hours relatively in both fasted & non fasted state. Food will decrease the bioavailability slightly
Volume of distribution is 20 to 40L Nearly 98 to 99% of drug ritonavir is binds to human plasma protein.
Isopropylthiazole oxidation is the major metabolite of ritonavir and it is similar in action of ritonavir. CYP3A is a major isoenzymes involved in the metabolism of ritonavir.
The excretion of ritonavir should be occurs through urine & feces as an unchanged form The ritonavir half life period is 3 to 5 hours
Interaction of drugs which are metabolized by CYP3A causes increasing the plasma concentration of these agents. Interaction of Ritomune with HIV-1 protease inhibitors causes increasing effect of concentration of these drugs. Ritomune interaction with integrase inhibitors, causes decreasing the effect of concentration of these drugs. Concomitant use with analgesic causes increasing concentration of analgesics. Ritomune interaction with anti-cancer or anti-arrhythmic drugs causes increasing the effect of concentration of these drugs. Interaction of Ritomune with warfarin causes either decreasing or increasing the concentration of warfarin. Interaction of Ritomune with anti-convulsants, anti-depressants causes increasing in concentration of these drugs .
No special antidote is required for over dosage If occurs then Provide patients supportive measure to the patient with over dosage of Ritonavir. Monitor the manifestation associated to over dosage condition of Ritomune. Ritonavir is intensively metabolized and largely binds to human plasma protein so hemodialysis process is not valuable for over dosage of ritonavir.
Serious adverse reactions may occur due to drug interactions like Ritomune with CYP3A inducers or inhibitors Hepatic toxicity Pancreatitis Allergic reactions PR interval extension Lipid disorders Diabetes mellitus Immune reconstitution syndrome Fat redistribution Hemophilia Cross resistance These are all some serious effects occurred during the therapy with Ritomune, to over come the problems patients must be; Provide with supportive measures Counsel about the adverse effect before starting the treatment In severe condition, stop the treatment. Maintain the lab value Patient should be frequently monitoring with the signs & symptoms associated to particular effects.
Patient must get advice from physician to avoid the over dosage problem, in case of missed dose. Follow the regular dosing schedule prescribed by physician.
Edema, Gout, Increased cholesterol, Increased triglycerides Liver toxicity, Pancreatitis, Allergic reactions, Blurred vision, Abdominal pain, Hypersensitivity reactions, Lipodystrophy, Arthralgia, Myopathy, Dyspepsia, Flatulence, GI hemorrhage, Gastro esophageal reflux disease, Nausea, Vomiting, Fatigue, Increased bilirubin, Hepatitis, Myalgia, Acne, Pruritus, Rash, Flushing, Hypertension, Hematocrit, Decreased hemoglobulin, Neutropenia, Dehydration, Cushing’s syndrome, Cardiac problems, Epidermal necrolysis.