Antihypertensive agent interaction

Drugs that may interact with antipsychotics include alcohol, CNS depressants, antihypertensive agents, dopamine, epinephrine, and charcoal. 

Numerous drug-drug interactions have been reported with the antipsychotic agents. These may be mediated through pharmacodynamic effects. For example, antipsychotics that block aj-adrenergic receptors may potentiate the antihypertensive effects of prazosin, labetalol, and some other antihypertensive agents. Conversely, antipsychotics associated with a2-adrenergic receptor blockade may interfere with the antihypertensive effects of clonidine and methyldopa (Richelson, 1999). 

Drug Interactions Other antihypertensive agents Carbamazepine (vasodilators, ACE inhibitors, Rifampin diuretics, and beta-blockers) Phenobarbital Digoxin Cyclosporine Disopyramide Theophylline Flecainide Inhalation anesthetics Quinidine Neuromuscular blocking agents Cimetidine Lithium ... 

The new antihypertensive agents 194 and 195, which function in part through interaction with a-andrenoreceptors198, have been 14C-labelled199 in three steps starting from ethylene-14C2 oxide (equation 77). The overall radiochemical yields for 194 and 195 were 69% and 62%, respectively, and the specific activities of both compounds before final dilutions were initialy 22.6 mCi mmol-1. 

Narayan P, Man In t Veld AJ. Clinical pharmacology of modern antihypertensive agents and their interaction with alpha-adrenoceptor antagonists. Br J Urol 1998 81(Suppl 1) 6-16. 

Ibuprofen interacts with antihypertensive agents, reducing their efficacy (27). 

This is a good example of where a theoretical interaction is being used to treat the patient. In this case, the patient s hypertension (high blood pressure) cannot be controlled with one drug. The prescriber has added a second antihypertensive agent to further lower the patient s blood pressure. Therefore, in this case it is appropriate that the patient takes both drugs. 

Other drug interactions have pharmacodynamic explanations. For example, fi antagonists and Ca channel blockers have additive effects on the cardiac conducting system. Additive effects on blood pressure between fi blockers and other antihypertensive agents often are employed to... 

V. Drug or laboratory interactions. A hypotensive effect is potentiated by other antihypertensive agents and inhalational anesthetics. 

The interaction of thiols (including cysteine and GSH) with metals, especially Fe (II), enhances the reduction ability of thiols considerably superoxide and thiyl radicals can be formed, as well as hydroxyl radicals [88]. Xenobiotic thiols such the antihypertensive agent, captopril (l-(3-mercapto-2-methyl-l-oxo-propyl)-L-proline) can also similarly form thiyl radicals [89]. 

VMATs are irreversibly inhibited by the potent antihypertensive drug reserpine. The depressive effects of reserpine helped to formulate the original monoamine hypothesis of affective disorders. Reseipine also appears to interact with the transporters near the site of substrate recognition. Tetrabenazine, which is used in treatment of movement disorders, inhibits VMAT2 much more potently than VMAT1, consistent with the less hypotensive action of this agent. 

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