Ritonavir Pharmacology

Ritonavir

About Ritonavir
HIV Protease Inhibitor, Thiazole derivative, Antiretroviral.
Mechanism of Action of Ritonavir
Ritonavir is a peptide analogue. It reversibly binds to the catalytic site of HIV encoded aspartyl protease enzyme which is involved in the degradation of poly protein into structural protein and subsequent maturation of virus particle. Binding of Ritonavir to the enzyme results in immature noninfectious viral progeny
Pharmacokinets of Ritonavir
Absorption: It is rapidly absorbed after oral administration. Distribution: It is distributed as protein bound form. Metabolism: It undergoes metabolism in the liver. Excretion: It is excreted primarily through faeces and small amount through urine
Onset of Action for Ritonavir
N/A
Duration of Action for Ritonavir
N/A
Half Life of Ritonavir
3- 5 hours
Side Effects of Ritonavir
1. Diarrhoea
2. Anorexia
3. Nausea
4. Vomiting
5. Abdominal pain
6. Paresthesia
7. Rash
8. Dizziness
9. Headache
10.Thrombocytopenia
11. Taste disturbances
Contra-indications of Ritonavir
1. Hypersensitivity to Ritonavir
Special Precautions while taking Ritonavir
1. Hepatic dysfunction
2. Diabetes mellitus
3. Haemophilia
4. Patient with high cholesterol and triglycerides level
Pregnancy Related Information
Use with caution
Old Age Related Information
Use with caution
Breast Feeding Related Information
Contraindicated
Children Related Information
Use with caution
Below 12: contraindicated
Indications for Ritonavir
HIV infection
Interactions for Ritonavir
Analgesics: Plasma concentration of dextroprop-oxyphene, pethidine and piroxicam increased (risk of toxicity-avoid concomitant use); plasma concentrations of other opioid analgesics (except methadone) and other NSAIDs possibly increased; plasma concentration of methadone reduced.
Anti-arrhythmics: Increased plasma concentration of amiodarone, flecainide, propafenone and quinidine (increased risk of ventricular arrhythmias-avoid concomitant use); possibly increased risk of arrhythmias with disopyramide and mexiletine.
Antibacterials: Plasma concentration of rifabutin increased by ritonavir (risk of uveitis-avoid concomitant use); plasma concentration of clarithromycin and possibly other macrolides increased.
Anticoagulants: Plasma concentration of warfarin and other anticoagulants possibly increased by ritonavir.
Antidepressants: Plasma concentration of SSRIs and tricyclics possibly increased; plasma concentration reduced by St John s wort (avoid concomitant use).
Antidiabetics: Plasma concentration of tolbutamide possibly increased.
Antiepileptics: Plasma concentration of carbamazepine possibly increased
Antifungals: Plasma concentration of ketoconazole and possibly other imidazoles and triazoles increased.
Antihistaminics: Increased risk of arrhythmias with terfenadine - avoid concomitant use
Antipsychotics: Increased plasma concentration of pimozide (risk of ventricular arrhythmias); increased plasma concentration of clozapine.
Other antivirals: Combination with nelflnavir may lead to increased plasma concentration of either drug; ritonavir increases plasma concentration of indinavir and saquinavir; increased risk of toxicity with efavirenz (monitor liver function tests).
Anxiolytics and Hypnotics: Plasma concentration of alprazolam, clorazepate, diazepam, flurazepam, midazolam and zolpidem increased.
Ergotamine and Ergometrine: Risk of ergotism-avoid concomitant use.
5HT1 Agonists: Plasma concentration of eletriptan increased (avoid concomitant use).
Lipid-regulating Drugs: Increased risk of myopathy with simvastatin.
Oestrogens and Progestogens: metabolism accelerated by ritonavir (contraceptive effect of combined oral contraceptives reduced)
Theophylline: Metabolism accelerated by ritonavir (reduced plasma-theophylline concentration).
Typical Dosage for Ritonavir
Adult 1.2 g / day in 2 divided dose; given with other antiretroviral agents
Schedule of Ritonavir
H
Storage Requirements for Ritonavir
Keep at 2 - 8 degree C for long term storage. If the drug is used with in 1 month then it can be store at 15 - 30 degree C in a tightly closed container. Protect away from heat and light. Keep out of the reach of children.
Effects of Missed Dosage of Ritonavir
Take the missed dose as soon as noticed and if it is the time to take the next dose then skip the missed dose.
Effects of Overdose of Ritonavir
Give supportive measures and treatment. Induce emesis or gastric lavage has to be done followed by charcoal administration.

Home Delivery for Ritonavir in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including ritonavir.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for ritonavir and other medicines and health products. Home delivery services for ritonavir may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take ritonavir only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for ritonavir before they complete the sale. You can get this information while placing the order for ritonavir with the pharmacy.

Ritonavir is a generic medicine name and there are several brands available for it. Some of the brands for ritonavir might be better known than ritonavir itself. If the pharmacy that's willing to deliver medicines to your home doesn't have ritonavir in stock, you can ask for one of the branded alternatives for ritonavir.