HIV Pharmacology and Drug Interactions

 
 

HIV Pharmacology and Drug Interactions

  • Tenofovir/Abacavir Drug Interaction? What is causing the high failure rates in some studies testing combinations that contain both these antiretroviral drugs?
  • Therapeutic Drug Monitoring in HIV Infection Therapeutic drug monitoring is becoming more widely used in HIV management, but experts remain divided regarding its routine clinical use.
  • Combining Saquinavir With Lopinavir/Ritonavir? What is the current dose(s) suggested for combining lopinavir/ritonavir with saquinavir?
  • Interactions Between Heroin and Antiretrovirals? How are antiretroviral drugs most likely to be affected by concurrent heroin use?
  • Ask the Experts - Food Effects on Protease Inhibitor Bioavailability? What are the effects of food on HIV medication? Among the nucleoside reverse transcriptase inhibitors, didanosine has food interactions, as does the nonnucleoside reverse transcriptase inhibitor efavirenz, and every single protease inhibitor (PI). However, it has been said that food restrictions on PIs may be removed when the drug is used with ritonavir boosting. Is this correct?
  • Ask the Experts - Protocol for Routine Therapeutic Drug Monitoring? Several patients have inquired about therapeutic drug monitoring (TDM) for their antiretroviral therapy. Based on currently available data, what would be a "reasonable" protocol for the use of TDM in routine clinical practice?
  • Ask the Experts - Interactions Between Bupropion and Antiretrovirals? Many HIV-infected patients receiving antiretroviral therapy are smokers and request prescriptions for bupropion. Apart from the obvious contraindication if patients are on ritonavir, what other potential drug interactions should one be aware of?
  • Ask the Experts - Use Additional Antacid With Didanosine Tablets? Didanosine pediatric oral solution has to be mixed with an equal volume of antacid before administration. Can we do the same with didanosine dispersible tablets, in order to minimize gastric adverse effects?
  • Ask the Experts - Medications for Osteopenia? A long-time HIV patient has an abnormal bone densitometry report reflecting osteopenia and had begun alendronate (Fosamax). The problem is that alendronate has specific restrictions about coadministration with foods and other medications, with the net result that the patient has stopped the alendronate. How important are the restrictions on alendronate -- such as recommendations about not
  • Ask the Experts - Space Out Drug Discontinuations Prior to "Drug... If someone on zidovudine/lamivudine (Combivir) and efavirenz wants to go off medications for a "holiday," I presume she should stop the efavirenz and continue the zidovudine/lamivudine for a few days to prevent exposure to just efavirenz. How long should she just take zidovudine/lamivudine before stopping it?
  • Ask the Experts - Dosing Phenytoin With PIs or NNRTIs? Do you have any specific advise on dosing protease inhibitors (PIs) or nonnucleoside reverse transcriptase inhibitors (NNRTIs) in a patient who absolutely requires phenytoin?
  • Ask the Experts - Dosing Efavirenz in Combination With Rifampin? Is it necessary to increase the dose of efavirenz (from 600-800 mg) when given in combination with rifampin?
  • Ask the Experts - Interactions Between Milk Thistle and Antiretrovirals? Are there any known interactions between milk thistle and drugs used in HAART?
  • Ask the Experts - Dosing TB drugs in Patients Receiving Dual PIs? What is the correct dosage of rifabutin to use daily or biweekly as part of the 2 months' prophylaxis for a positive PPD, when the combination ritonavir/indinavir is used as part of the treatment for HIV?
  • Ask the Experts - Twice-Daily Dosing of Fortovase? Four hundred of the 900 patients at our AIDS clinic in Mexico are receiving Fortovase. We are considering using a dose of 1600 mg twice daily, rather than the recommended dose of 1200 mg three times daily, which may give us a small cost saving. What do you think about this decision?
  • Ask the Experts - Can I Dose Delavirdine Twice Daily? I am interested in dosing delavirdine (Rescriptor) twice daily for some of my patients, particularly those who will also be on amprenavir (Agenerase). Can you comment on this type of dosing?
  • Ask the Experts - Include Mycophenolate in Abacavir-Containing Salvage... I have a patient with advanced immunosuppression (CD4 40, HIV RNA = 276,000) who requires a salvage regimen, having failed on multiple treatments in the past.