التداخل بين إرغوتامين وكافيين ولابيتالول

The beta-blocker Inderal (propranolol) has been reported to potentiate the vasoconstrictive action of ergotamine tartrate and caffeine tablets by blocking the vasodilating property of epinephrine.

Labetalol has also been reported to produce a false-positive test for amphetamine when screening urine for the presence of drugs using the commercially available assay methods.

When patients being treated with labetalol have a positive urine test for amphetamine using these techniques, confirm using more specific methods, such as a gas chromatographic-mass spectrometer technique.