Loperamide adverse effects

In a double-blind, placebo-controlled study, 12 healthy subjects were given a single 600-mg dose of ritonavir with either loperamide 16 mg or placebo. The loperamide AUC and maximum plasma level were increased threefold and 17%, respectively, by ritonavir, but no additional CNS adverse effects were seen. Anotiier study in 20 healthy subjects looked at the pharmacokinetics and pharmacodynamics of a single 16-mg dose of loperamide taken with either tipranavir 750 mg twice daily, ritonavir 200 mg twice daily or both drugs together. (Note that this dose of tipranavir is higher than tiie usual ritonavir-boosted dose of 500 mg twice daily.) Tipranavir alone reduced the maximum concentration and AUC of loperamide by 58% and 63%, respectively, whereas ritonavir increased these parameters by 83% and 121%, respectively. The combination of tipranavir/ritonavir, as is usual clinical practice, resulted in a net reduction in the maximum concentration and AUC of loperamide by 61% and 51%, respectively, similar to the effect seen with tipranavir alone. The maximum concentration and AUC of the metabolites of loperamide were also reduced. There were no clinically significant loperamide adverse effects on respiration or pupil contractility with either ritonavir alone, tipranavir alone, or the combination. ... 

Other potential adverse effects include impaired absorption of fat-soluble vitamins A, D, E, and K hypernatremia and hyperchloremia GI obstruction and reduced bioavailability of acidic drugs such as warfarin, nicotinic acid, thyroxine, acetaminophen, hydrocortisone, hydrochlorothiazide, loperamide, and possibly iron. Drug interactions may be avoided by alternating administration times with an interval of 6 hours or greater between the BAR and other drugs. 

PROTEASE INHIBITORS ANTIDIARRHOEAL DRUGS-LOPERAMIDE t risk of adverse effects when loperamide is co-ingested with ritonavir Ritonavir inhibits P-gp and CYP3A4 Monitor for clinical effect, and consider 1 dose if necessaiy. Stop if there are signs of abdominal distension in HIV patients as toxic megacolon has been reported... 

Adverse effects of loperamide are constipation, abdominal cramps, drowsiness and dizziness. 

Ritonavir increases the piasma levels of loperamide. Tipranavir, aione and combined with ritonavir, reduces the bioavailability and piasma ieveis of ioperamide and its metabolites. No central opioid adverse effects are seen when loperamide is given with ritonavir aione, tipranavir aione, or tipranavir/ritonavir. 

Irinotecan treatment schedules differ from 125 to 150 mg/m2 once a week for 4 wk followed by a 2-wk drug free interval (United States), to 350 mg/m2 once every 3 wk (Europe), or 100 mg/m2/wk or 150 mg/m2 every 2 wk (Japan). Differing intermittent treatment schedules using cytokine support for neutropenia, or intensive loperamide to counteract diarrhea, have also been reported (14). These tolerable CPT-11 regimens have produced median durations of response that range from 5.6 to 10.6 mo in colorectal patients disease stabilization occurs in 30 to 71 % (40). Response rates of 26% and 32% have been reported for previously untreated colorectal cancer patients higher response rates have been reported for non-5-FU-refractory patients (only 7-21%). Symptoms of diarrhea, nausea, and vomiting are common toxicities other side effects are asthenia, abdominal pain, leukopenia, and neutropenia. In the US trials at least one of these adverse... 

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