The steady-state plasma pharmacokinetics of indinavir alone and in combination with a low dose of ritonavir in twice daily dosing regimens in HIV-1-infected individuals. 1999

R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
Department of Pharmacy and Pharmacology, Slotervaart Hospital, Amsterdam, The Netherlands.

OBJECTIVE To explore the steady-state plasma pharmacokinetics of indinavir in twice daily dosing regimens with and without the co-administration of 100 mg ritonavir. METHODS Observational pharmacokinetic study. METHODS HIV-1-infected individuals who use indinavir alone (1200 mg twice daily, n = 6), or the combination of 100 mg ritonavir twice daily plus either 800 mg (n = 6), or 1200 mg indinavir twice daily (n = 2). METHODS Steady-state pharmacokinetics of indinavir and ritonavir were assessed by drawing 12 blood samples during an 8-h period after ingestion of the medication. RESULTS Significant differences were observed for indinavir pharmacokinetics between the dosing regimens indinavir 1200 mg twice daily alone and indinavir/ ritonavir 800/100 mg twice daily with respect to the mean trough concentration (0.21 and 0.99 microg/ml, respectively, P = 0.002), the mean maximum concentration (13.79 and 8.74 microg/ml, respectively, P = 0.028), and for the mean plasma elimination half-life (1.6 and 3.2 h, respectively, P = 0.001). The combination indinavir/ritonavir 1200/100 mg twice daily led to very high exposure to indinavir and was not well tolerated. However, the combination indinavir/ritonavir 800/100 mg twice daily was well tolerated and resulted in therapeutic concentrations of indinavir with improved trough concentrations and similar maximum concentrations as observed with the licensed dosage of 800 mg three times daily. CONCLUSIONS Combination of indinavir and 100 mg ritonavir in twice daily dosing regimens significantly affects the pharmacokinetic profile of indinavir. The results of this observational study provide a pharmacologic basis for the combination of indinavir (800 mg) and ritonavir (100 mg) in twice daily dosing regimens.

UI MeSH Term Description Entries
D008297 Male Males
D008875 Middle Aged An adult aged 45 - 64 years. Middle Age
D004334 Drug Administration Schedule Time schedule for administration of a drug in order to achieve optimum effectiveness and convenience. Administration Schedule, Drug,Administration Schedules, Drug,Drug Administration Schedules,Schedule, Drug Administration,Schedules, Drug Administration
D004359 Drug Therapy, Combination Therapy with two or more separate preparations given for a combined effect. Combination Chemotherapy,Polychemotherapy,Chemotherapy, Combination,Combination Drug Therapy,Drug Polytherapy,Therapy, Combination Drug,Chemotherapies, Combination,Combination Chemotherapies,Combination Drug Therapies,Drug Polytherapies,Drug Therapies, Combination,Polychemotherapies,Polytherapies, Drug,Polytherapy, Drug,Therapies, Combination Drug
D005260 Female Females
D006801 Humans Members of the species Homo sapiens. Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328 Adult A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available. Adults
D015497 HIV-1 The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte. Human immunodeficiency virus 1,HIV-I,Human Immunodeficiency Virus Type 1,Immunodeficiency Virus Type 1, Human
D015658 HIV Infections Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS). HTLV-III Infections,HTLV-III-LAV Infections,T-Lymphotropic Virus Type III Infections, Human,HIV Coinfection,Coinfection, HIV,Coinfections, HIV,HIV Coinfections,HIV Infection,HTLV III Infections,HTLV III LAV Infections,HTLV-III Infection,HTLV-III-LAV Infection,Infection, HIV,Infection, HTLV-III,Infection, HTLV-III-LAV,Infections, HIV,Infections, HTLV-III,Infections, HTLV-III-LAV,T Lymphotropic Virus Type III Infections, Human
D019438 Ritonavir An HIV protease inhibitor that works by interfering with the reproductive cycle of HIV. It also inhibits CYTOCHROME P-450 CYP3A. ABT 538,ABT-538,Norvir,ABT538

Related Publications

R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
January 2005, Antiviral therapy,
R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
September 2005, British journal of clinical pharmacology,
R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
July 2003, HIV medicine,
R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
January 2010, HIV clinical trials,
R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
June 2000, AIDS (London, England),
R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
January 2002, Clinical pharmacology and therapeutics,
R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
December 2011, Journal of acquired immune deficiency syndromes (1999),
R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
September 2000, AIDS (London, England),
R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
October 2004, Antiviral therapy,
R P van Heeswijk, and A I Veldkamp, and R M Hoetelmans, and J W Mulder, and G Schreij, and A Hsu, and J M Lange, and J H Beijnen, and P L Meenhorst
December 1998, AIDS (London, England),
Copied contents to your clipboard!