Hypertension hypertensive crisis

Chronic use of these irreversible MAO inhibitors has been associated with life-threatening toxicity, ie, hepatotoxicity and hypertensive crisis. Interactions with tyramine contained in food and other drugs have severely limited use of irreversible MAO inhibitors. These MAO inhibitors are also nonselective, inhibiting both MAO-A and MAO-B isoenzymes. Furthermore, they interfere with the hepatic metabolism of many dmgs. 

As of the mid-1990s, use of MAOIs for the treatment of depression is severely restricted because of potential side effects, the most serious of which is hypertensive crisis, which results primarily from the presence of dietary tyramine. Tyramine, a naturally occurring amine present in cheese, beer, wine, and other foods, is an indirecdy acting sympathomimetic, that is, it potently causes the release of norepinephrine from sympathetic neurons. The norepinephrine that is released interacts with adrenoceptors and, by interacting with a-adrenoceptors, causes a marked increase in blood pressure the resultant hypertension may be so severe as to cause death. 

Two important pathways for catecholamine metaboHsm are 0-methylation by COMT, which is cytoplasmicaHy localized, and oxidative deamination by the mitochondrial localized enzyme MAO. There are large amounts of MAO in tissues such as the fiver and the heart which are responsible for the removal of most of the circulating monoamine, including some taken in from the diet. Tyramine is found in high concentrations in certain foods such as cheese, and in wine. Normally, this tyramine is deaminated in the fiver. However, if MAO is inhibited, the tyramine may then be converted into octopamine [104-14-37] which may indirecdy cause release of NE from nerve terminals to cause hypertensive crisis. Thus MAO, which is relatively nonspecific, plays an important role in the detoxification of pharmacologically active amines ingested from the diet. 

The amphetamines and the anorexiants should not be given during or within 14 days after administration of monoamine oxidase inhibitors (see Chap. 31) because the patient may experience hypertensive crisis and intracranial hemorrhage. When guanethidine is administered with the amphetamines or the anorexiants, the antihypertensive effect of guanethidine may decrease. Coadministration of the amphetamines or the anorexiants with the tricyclic antidepressants may decrease the effects of the amphetamines or the anorexiants. 

Levodopa interacts with many different drugs. When levodopa is used with phenytoin, reserpine, and papaverine, there is a decrease in response to levodopa The risk of a hypertensive crisis increases when levodopa is used with the monoamine oxidase inhibitors (see Chap. 31). Foods high in pyridoxine (vitamin B6) or vitamin B6 preparations reverse the effect of levodopa However, when carbidopa is used with levodopa, pyridoxine has no effect on the action of levodopa hi fact, when levodopa and carbidopa are given together, pyridoxine may be prescribed to decrease the adverse effects associated with levodopa... 

One serious adverse reaction associated with the use of the MAOIs is hypertensive crisis (extremely high blood pressure), which may occur when foods containing tyramine (an amino acid present in some foods) are eaten (see Home Care Checklist Avoiding Drug Food Interactions With MAOIs). 

One of the earliest symptoms of hypertensive crisis is headache (usually occipital), followed by a stiff or sore neck, nausea, vomiting, sweating, fever, chest pain, dilated pupils, and bradycardia or tachycardia. If a hypertensive crisis occurs, immediate medical intervention is necessary to reduce the blood pressure Strokes (cerebrovascular accidents) and death have been reported. 

Orthostatic hypotension, vertigo, dizziness, nausea, constipation, dry mouth, diarrhea, headache, restlessness, blurred vision, hypertensive crisis Orthostatic hypotension, vertigo, dizziness, nausea, constipation, dry mouth, diarrhea, headache, restlessness, blurred vision, hypertensive crisis... 

If your patients are taking MAOIs, they need to avoid foods containing tyramine. Otherwise they may experience a life-threatening reaction, hypertensive crisis. Be sure to instruct ycur patients to avoid the following foods ... 

MAO Is The MAOIs are less frequently prescribed than other antidepressants, probably because of the risk of hypertensive crisis when food containing tyramine is ingested during M AOI therapy. Fhtients receiving MAOIs... 

M AO Is. The MAOIs are not widely used because of their potential for serious adverse reactions. Fhtients receiving MAOIs require strict dietary control because foods containing tyramine should not be eaten because of the danger of a hypertensive crisis. (See Home Care Checklist Avoiding Drug-Food Interactions With MAOIs). 

Complaints of a headache (especially an ocdpital headache) may indicate the occurrence of a hypertensive criss. The nurse should take the blood pressure and, if it is elevated, notify the primary health care provider immediately. The nurse should monitor the blood pressure at 15- to 30-minute intervals. The primary health care provider must be notified of any additional symptoms of hypertensive crisis. 

Additive sympathomimetic effects may develop when decongestants are administered with other sympathomimetic drug s (see Chap. 22). Use of the nasal decongestants with the MAOIs may cause hypertensive crisis. Use of a decongestant with beta-adrenergic blocking dragp may cause hypertension or bradycardia. When ephedrine is administered with theophylline, the patient is at increased risk for theophylline toxicity. 

The antidiarrheal drugs cause an additive CNS depression when administered with alcohol, antihistamines, narcotics, and sedatives or hypnotics. There are additive cholinergic effects when administered with other drugp having anticholinergic activity, such as antidepressants or antihistamines. Concurrent use of the antidiarrheals witii a monoamine oxidase inhibitor increases the risk of a hypertensive crisis. 

Paramethoxyamphetamine (PMA) has a hallucinogenic potency about five times that of mescaline and three times that of MDA. Because of its high toxicity, it caused fatal intoxications shortly after it became available on the street in the early 1970s (Cimbura 1974). Some of the fatalities were apparently due to the fact that the substance was sold to users as MDA because of the higher potency of PMA, severe intoxication (i.e., hypertensive crisis, seizures, death) occurred. 

Inexperienced users or individuals who are exposed to the drug unexpectedly (e.g., who unknowingly consume PCP-adulterated cannabis) may develop severe anxiety and panic because of the intensity and variety of symptoms. Perceptual distortions have sometimes led to extremely violent behavior, accidents, or self-damaging acts. An especially high risk of violent behavior has been reported in acutely intoxicated PCP users who have a history of psychiatric problems. Intoxication with doses in excess of 150 mg may lead to convulsions, coma, and death from respiratory arrest. Other complications include hypertensive crisis, intracerebral hemorrhage, and renal failure (Table 6-5). 

In overdose, ketamine may lead to hyperthermia, seizures, hypertensive crisis, coma, and even death. These symptoms are generally thought to be caused by ketamine s catecholaminergic effects (Reich and Silvay 1989). Ketamine is physically addicting, with a described withdrawal syndrome. 

MAO has been inhibited. As a result, transmitter accumulates in the cytoplasm and is exported into the synapse via the membrane-bound transporter. The ensuing (impulse-independent) sympathetic arousal can be disastrous, culminating in a hypertensive crisis and stroke. Although this process is a pharmacological curiosity and certainly contributed to the demise of MAOIs, it is possibly overrated (Tyrer 1979) it has been estimated that the number of deaths associated with the use of the MAOI, tranylcypromine, amounts to only 1 per 14000 patient years. However, this sequence of events echoes exactly the acute actions of methylenedioxymethamphetamine (MDMA, Ecstasy ) and undoubtedly accounts for some of the deaths attributed to this drug. 

Eastman, J.W., and Cohen, S.N. Hypertensive crisis and death associated with phencyclidine poisoning. JAMA 231 1270-1271, 1975. 

Create a care plan for DW s hypertensive crisis. This should include (1) acute goals of therapy, (2) a patient-specific therapeutic plan to achieve goals, and (3) a plan for appropriate outpatient follow-up including recommendations for changes, if any, to current medications. 

MAOIs Pharmacodynamic—hypertensive crisis Tyramine-rich foods Sympathomimetics... 

MAO Is have not been evaluated systematically for treatment of PD under the current diagnostic classification and generally are reserved for patients who are refractory to other treatments.48,49 MAOIs have significant side effects that limit adherence. Additionally, patients must adhere to dietary restriction of tyramine and avoid sympathomimetic drugs to avoid hypertensive crisis. 

Myelosuppression is the major side effect. Nausea, vomiting, and a flulike syndrome occur initially with therapy. Patients must be counseled to avoid tyramine-rich foods because procarbazine is a monoamine oxidase inhibitor. Patients should be provided a list of foods and beverages to avoid to prevent a hypertensive crisis. A disulhramlike reaction can occur with the ingestion of alcohol. 

Phentermine use should be avoided in patients concomitantly receiving or having received an MAOI within the preceding 14 days. Combination therapy with any stimulant or MAOI has the potential for causing hypertensive crisis. Alcohol is not recommended for patients prescribed phentermine.38... 

Synergy of unwanted pharmacological effect ginseng and its products will inhibit the central nervous system (CNS) when they are applied with luminal, chloral hydrate, or ephedrine, which can increase the release of dopamine, noradrenaline, and serotonin in the CNS thus inducing a hypertensive crisis if monoamine oxidase inhibitors (MAOIs) are given simultaneously. 

MAO inhibitors and foods containing ty ramine—hypertensive crisis... 

The answer is d. (Hardman, pp 794-795.) Hydralazine, minoxidil, diazoxide, and sodium nitroprusside are all directly acting vasodilators used to treat hypertension. Because hydralazine, minoxidil, nifedipine, and diazoxide relax arteriolar smooth muscle more than smooth muscle in venules, the effect on venous capacitance is negligible. Sodium nitroprusside, which affects both arterioles and venules, does not increase cardiac output, a feature that enhances the utility of sodium nitroprusside in the management of hypertensive crisis associated with MI. 

The answer is b. (Hardmanr p 444.) This patient ate tyramine-rich foods while taking an MAOI and went into hypertensive crisis. Tyramine causes release of stored catecholamines from presynaptic terminals, which can cause hypertension, headache, tachycardia, cardiac arrhythmias, nausea, and stroke. In patients who do not take MAOls, tyramine is inactivated in the gut by MAO, and patients taking MAOls must be warned about the dangers of eating tyramine-rich foods. 

Hypertensive crisis is a potentially fatal adverse reaction that can occur when MAOIs are taken concurrently with certain foods, especially those high in... 

Increased or decreased antidepressant response increased toxicity Decreased antihypertensive efficacy Decreased antihypertensive efficacy Increased hypoglycemic effects Possible additive lowering of seizure threshold Decreased antihypertensive efficacy tachycardia CNS stimulation Increased therapeutic and possibly toxic effects of both drugs hypertensive crisis delirium seizures hyperpyrexia serotonin syndrome Increased hypoglycemic effects... 

Venlafaxine MAOIs Potential for hypertensive crisis, serotonin syndrome, delirium... 

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