Insulin therapy drug interactions

AMPHETAMINES BUPROPION 1. t plasma concentrations of these substrates, with risk of toxic effects 2. t risk of seizures. This risk is marked in elderly people, patients with a history of seizures, those with an addiction to opiates/ cocaine/stimulants, and those with diabetes treated with oral hypoglycaemics or insulin 1. Bupropion and its metabolite hydroxybupropion inhibit CYP2D6 2. Bupropion is associated with a dose-related risk of seizures. These drugs that lower seizure threshold are individually epileptogenic. They have additive effects when combined 1. Initiate therapy with these drugs, particularly those with a narrow therapeutic index, at the lowest effective dose. Interaction is likely to be important with substrates for which CYP2D6 is considered the only metabolic pathway (e.g. amphetamines) 2. Extreme caution. The dose of bupropion should not exceed 450 mg/day (or 150 mg/day in those with severe hepatic cirrhosis)... 

Most antihistamines possess anticholinergic properties that by themselves are of minor intensity but may increase considerably if given together with MAOIs. Interactions of MAOIs with antihypertensives (e.g., reserpine-type drugs) and oral antidiabetic drugs, as well as insulin and L-dopa, have all been encountered. It can be seen why MAO inhibitors are not viewed today as initial therapy except possibly in atypical depression. Certain panic and phobic reactions respond well. An important indication would be in case of therapeutic failures with the tricyclic or other heterocyclic antidepressants. 

Ankle edema occurred in about 5% of patients treated with both rosiglitazone and pioglitazone in some cases, pulmonary edema can develop. Edema was more frequent in insulin combination therapy with either drug (about 15% compared with 5.4-7% with insulin alone). The reasons for fluid retention and peripheral edema with TZDs are multifactorial. The increase in plasma volume may result from a reduction in renal excretion of sodium and an increase in sodium and free water retention. TZDs may also interact synergistically with insulin to cause arterial vasodilatation, leading to sodium reabsorption and an increase in extracellular volume [61,62], In case reports, the edema has not been responsive to diuretics [63,64]. 

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