1. Anti retroviral Pharmacology dr shabeel pn

3. Mechanism of Action of ARVs Illustration by David Klemm Fusion Inhibitor & Chemokine Receptor Antagonist NNRTI NRTI Protease Inhibitor Integrase Inhibitor

4. Antiretroviral Drug Approval: 1987 - 2007 AZT ddI ddC d4T 3TC SQV RTV IDV NVP NFV DLV EFV ABC APV LPV/r TDF T-20 TPV DRV Maraviroc Raltegravir ATV FTC FPV

5. Liver Metabolism 25% Adapted from Br J Clin Pharmacol 1998:46:101-110 Pgp small bowel gut lumen sinusoid portal vein hepatic vein 100% 3A4 CYP 100% 100% 100% 50% 50% 50% 25%

9. NRTIs *dose reduce for renal dysfunction Few SEs, renal toxicity hypersensitivity Peripheral neuropathy, Pancreatitis, LA/HS, Lipoatrophy, facial wasting Common Side Effects Renal Hepatic by alcohol dehydrogenase and glucuronyl transferase Renal Metabolism/ Elimination 300mg tabs, oral soln 300mg bid, 600mg qd Abacavir (ABC) Ziagen 300mg tabs 300mg qd* Tenofovir (TDF) Viread 15,20,30,40 mg cap,oral soln 40mg bid (  60kg) 30mg bid (<60kg) * Stavudine (d4T) Zerit IR Dosage forms Standard Dose* Drug

10. NRTI Combinations *dose reduce for renal dysfunction 600/300mg tabs 1 Tablet qd* Abacavir/Lamivudine Epzicom 300/200mg tabs 1 Tablet qd* Tenofovir/Emtricitabine Truvada 300/150/300mg tabs 1 Tablet bid* Abacavir/Lamivudine/Zidovudine (TZV) Trizivir 300/200/600 mg tabs 1 Tablet qd* Tenofovir/Emtricitabine/Efavirenz Atripla 150/300mg tabs 1 Tablet bid * Lamivudine/ Zidovudine (COM) Combivir Dosage forms Standard Dose* Drug

12. NNRTIs *Pregnancy Class D Vivid dreams, drowsiness or insomnia, rash (SJ), hyperlipidemia Rash (SJ), hepatotoxicity Rash Common AEs CYP3A, 2B6 inducer; 2B6, 3A4 substrate 50, 100, 200mg cap, 600mg tab 600 mg qhs Efavirenz* (EFV) Sustiva CYP3A inducer, auto inducer; 3A4, 2B6 substrate 200mg tabs, Oral susp 200 mg qd x 14 d then 200 mg bid Nevirapine (NVP) Viramune Potent CYP3A inhibitor; 3A4 substrate 100mg tab, 200mg cap 400 mg tid Delavirdine (DLV) Rescriptor Metabolism Dosage forms Standard Dose Drug

15. Lipodystrophy Illustrations “ Buffalo hump” “ Protease paunch” “ Facial wasting”

16. Use of Ritonavir as a P450 Inhibitor with PIs

17. Protease Inhibitors (1) Take with Food (2) Must be refrigerated ** All PIs except atazanavir can increase lipids and cause insulin resistance Dyspepsia, Nausea, vomiting, diarrhea, flatulence 3A, Pgp substrate; 3A inhibitor; 2C9, 2C19 inducer 200/50 mg tabs, 80/20mg/5mL soln 400/100 bid Lopinavir/ ritonavir (Kaletra) (1,2) 3A, Pgp substrate; weak 3A inhibitor 2C19 (M8  3A) substrate; weak 3A inhibitor 3A, Pgp substrate; weak 3A inhibitor Metabolism Nephrolithiasis  Drink 7-8 glasses of water per day; hyperbilirubinemia 100, 200, 333, 400mg caps 800/ rtv 100 bid, 800mg tid Indinavir (Crixivan) (1-when taken with rtv) Diarrhea 250mg, 625mg tabs, 50mg/g oral pwdr 1250 bid, 750mg tid Nelfinavir (Viracept) (1) GI intolerance 200mg caps, 500mg tabs 1000/ rtv 100 bid or 1600/ rtv 100 qd Saquinavir (Invirase) (1) Common AEs** Dosage Forms Standard Dose

18. Protease Inhibitors (1) Take with Food (2) Must be refrigerated ** All PIs except atazanavir can increase lipids and cause insulin resistance Diarrhea, nausea, HA, nasopharyngitis 3A4 substrate; 3A4 inhibitors 300mg tabs 600/100 RTV mg bid Darunavir (Prezista) (1) Hyperbilirubinemia, PR prolongation 3A substrate; 3A and UGT1A1 inhibitor 100, 150, 200mg caps 400qd or 300/ rtv 100qd Atazanavir (Reyataz) (1) Hepatotoxicity, Increased bleeding caution with sulfur allergy 3A4, Pgp substrate; 3A4, inducer/ inhibitor??; Pgp inducer 250mg caps 500/200 RTV mg bid Tipranavir (Aptivus) (1,2) Nausea, vomiting, diarrhea, GI upset 2D6, 3A4, Pgp substrate; 3A4, Pgp inhibitor 100mg caps; 80mg/mL Used as a PK booster 100-200mg Ritonavir (Norvir) (1,2) 3A4, Pgp substrate; 3A4 inducer/ Inhibitor Metabolism Rash, GI intolerance, caution with sulfur allergy 700mg tabs (Agenerase-APV liq available) 1400mg bid; 700/100 RTV mg bid; 1400/200 RTV mg qd Fosamprenavir (Lexiva) (1) Common AEs** Dosage Forms Standard Dose

20. New ARV Targets Against HIV

23. HIV Tropism

26. Drug Interactions

27. Antiretroviral Metabolism, Induction, and Inhibition Other enzymes 3A4 3A4, Pgp Tipranavir 3A4 3A4, Pgp Darunavir 3A4, Pgp Maraviroc 3A4, UGT, 1A2 3A4, Pgp Atazanavir 2C9, 2C19, 1A2 3A4 3A4, Pgp Lopinavir/ritonavir 3A4 (in vivo) 3A4 (in vitro) 3A4, Pgp Fosamprenavir 3A4 (in vivo) 3A4 (in vitro) 3A4, Pgp Amprenavir 3A4 2C19 (M8  3A4) Nelfinavir 3A4 3A4, Pgp Saquinavir 2D6 (at high doses only) 3A4, 2D6, Pgp 2D6, 3A4, Pgp Ritonavir 3A4 3A4, 2B6 Nevirapine 3A4, 2B6 3A4 2B6, 3A4 Efavirenz Induces Inhibits Substrate Drug

28. Cytochrome P450: Non-Antiretrovirals rifamycins, CBZ, phenytoin SSRIs, azoles, fluvastatin, omeprazole, topiramate Omeprazole, phenytoin 2C19 rifamycins, phenytoin, carbamazepine, St. John’s wort, aprepitant, garlic Cimetidine, Macrolides, FQs, SSRIs, CCB, azoles, aprepitant Macrolides,cyclosporine, CCB, statins, azoles, PDE5 inhibitors, aprepitant, midazolam, triazolam 3A4 rifamycins, phenytoin, CBZ, St. John’s wort Haldol, SSRIs, cimetidine, amiodarone Opiates, nortriptyline, amitriptyline, tramadol, trazodone, paroxetine, metoprolol, propranolol, carvedilol 2D6 Inducer Inhibitor Substrate Phenytoin, CBZ, rifammycins, aprepitant Amiodarone, SSRIs, azoles, amiodarone S-warfarin, sulfonylureas, phenytoin, carvedilol 2C9 rifamycins, phenytoin, CBZ, smoking, St. John’s wort FQs, azoles, macrolides, Amitriptyline, clozapine, caffeine, clozapine, imipramine, R-warfarin, theophylline, proprnaolol 1A2

30. Dose Adjustments Between ARVs Use RTV with FPV Fosamprenavir Efavirenz (Nevirapine) Increase LPV/RTV to 3 tabs BID Lopinavir/ritonavir Efavirenz (Nevirapine) Use RTV 100mg QD with ATV + EFV Atazanavir Efavirenz (Nevirapine) Use RTV 100mg QD with ATV + TDF Atazanavir Tenofovir Dose ddI as 250mg QD with TDF 300mg QD Didanosine Tenofovir Recommendation Drug B Drug A

32. Importance of Adherence

34. Why TDM in HIV therapy? Adapted from Acosta EP, et al AIDS Res Human Retro 2002