Treatment with the protease inhibitor Kaletra may cause opiate withdrawal symptoms in heroin addicts on methadone therapy, according to a study in the August 15 edition of Clinical Infectious Diseases. Kaletra can significantly lower the concentration of methadone in the blood, causing withdrawal symptoms, according to lead study author Elinore McCance-Katz of the Medical College of Virginia in Richmond. Methadone clearance from the body also was sped up when Kaletra was taken.
'I think the message for physicians treating [HIV-positive patients on methadone therapy] is that they need to be aware of all the patient's medications and any possible interactions,' McCance-Katz says. 'Informing the patient of possible interactions is particularly important because medication adherence is such a huge issue in this population.'
