Hypotension beta-adrenoceptor

Diclofenac is a non-steroidal anti-inflammatory drug. NSAIDs interact with both angiotensin-converting enzyme inhibitors, such as enalapril, and beta-adrenoceptor blockers, such as atenolol, resulting in antagonism to the hypotensive reaction, leading to a hypertensive reaction. NSAIDs interact with... 

Verapamil Beta-adrenoceptor blocking drugs Asystole, hypotension. 

Neuroleptic drugs can reduce or block the pressor effects of alpha-adrenoceptor agonists. When using drugs with both alpha- and beta-adrenoceptor activity, neuroleptic drug blockade of alpha-adrenoceptors can lead to unopposed beta predominance, resulting in severe hypotension (622). 

Although atenolol, a hydrophihc cardioselective beta-adrenoceptor antagonist with no partial agonist activity, is generally regarded as one of the safest beta-blockers, severe adverse effects are occasionally reported. These include profound hypotension after a single oral dose (1), organic brain syndrome (2), cholestasis (3), and cutaneous vascuhtis (4). 

The hypotensive effects of halothane and barbiturates can be exaggerated by beta-adrenoceptor antagonists. However, they are not contraindicated in anesthesia, provided the anesthetist is aware of what the patient is taking. 

A single intravenous dose of labetalol 30 mg given to a woman with severe pregnancy-related hypertension 20 minutes before cesarean section was associated with significant neonatal beta-adrenoceptor blockade (hypoglycemia, bradycardia, and hypotension), and there were high labetalol concentrations in the umbilical cord blood (150-180 ng/ml) (13). 

Metaraminol (2-10 mg intramuscularly) is used to treat serious hypotension. It has no noticeable central nervous effects and the beta-adrenoceptors of the heart usually do not react. The maximum effect of a dose is not at once apparent, and one should wait for some 10 minutes before deciding to give a further dose. In two patients an intravenous infusion of metaraminol to treat paroxysmal supraventricular tachycardia resulted in acute hypertension and pulmonary edema (1). Subcutaneous administration is risky and can result in dangerous sloughing. 

A severe and life-threatening hypotensive reaction in patients with quadriplegia after terbutaline medication warrants a warning against indiscriminate use of beta-adrenoceptor agonists in the absence of autonomic spinal function (SEDA-8,145). 

Drug adulteration Adulteration of heroin with clenbuterol is frequently reported [112 ]. In 13 confirmed cases of exposure to clenbuterol in this way, clenbuterol was identified in the blood and or urine of 12 [113 ]. Symptoms included nausea, chest pain, palpitation, dyspnea, and tremor. The physical findings included significant tachycardia and hypotension, and there was laboratory evidence of hyperglycemia, hypokalemia, and increased lactate concentrations six patients had biochemical evidence of myocardial injury. Ten were given beta-adrenoceptor antagonists without adverse effects. 

---