in vivo
Tetramisole (2 mg/kg, i.v.) after a delay of 20 s, produces a strong contraction of the nictitating membrane in the cat which is accompanied by a small brief fall in blood pressure followed by a sustained rise that persisted for up to 20 min. Tetramisole (2 mg/kg) elicites a greater contractile response in the membrane than in non-reserpinized cats. Tetramisole (5-10 mg/kg, i.v.) causes a sharp transient fall in blood pressure in rabbits which is partially antagonized by atropine. Tetramisole (15 mg/kg) rises the mean faecal egg count from 3 weeks after treatment and remaines continuously higher up to 12 weeks in sheeps.
Description
Tetramisole is a racemic mixture of levamisole and its enantiomer dexamisole, which is a specific inhibitor of tissue non-specific alkaline phosphatase (TNAP). This drug is used in veterinary to treat of ascariasis and other worm infections e.g hook-"ms. And also is used as an immunostimulant (in that case it is used for longer periods of time).
Biological Activity
Levamisole ((-)-Tetramisole) hydrochloride is an anthelmintic and immunomodulator belonging to a class of synthetic imidazothiazole derivatives. Levamisole hydrochloride has antiviral effects against HSV.
in vitro
Tetramisole is active at low, atoxic oral and parenteral dose levels against all adult and immature gastrointestinal and pulmonary nematodes tested in 14 different hosts. Tetramisole (10 μg/mL) causes a sustained contraction of the isolated somatic muscles of the worm. Tetramisole reduces the resting potential of Ascaris muscle from 34 mV to 10 mV. Tetramisole causes contraction of Ascaris muscle previously depolarized with high K+ solutions. Tetramisole (0.1 mM) augmentes the twitch responses of both the directly and indirectly stimulated muscle in cats. Tetramisole (0.1 mM) increases the twitch response of the preparation and reverses the blocking action of tubocurarine in chickens. Tetramisole (0.1 mM) produces reversible neuromuscular block and contracture of the muscle in chickens.
