Phenylpropanolamine hypertension with

Older drugs still available in some countries include phenylpropanolamine, benzphetamine, amphetamine, methamphetamine, phentermine, diethylpropion, mazindol, and phendimetrazine. These drugs are all amphetamine mimics and are central nervous system appetite suppressants they are generally helpful only during the first few weeks of therapy. Their toxicity is significant and includes hypertension (with a risk of cerebral hemorrhage) and addiction liability. 

Khurana V, de la Fuente M, Bradley TP. Hypertensive crisis secondary to phenylpropanolamine interacting with tripledrug therapy for HIV prophylaxis. Am J Med 1999 106(1) 118-19. 

Ephedrine —contraindicated with MAOIs Pseudoephedrine —contraindicated with MAOIs Phenylephrine —contraindicated with MAOIs Phenylpropanolamine —contraindicated with MAOIs Seriously elevated blood pressure (hypertensive crisis), elevated temperature, seizures, cerebral hemorrhage, death... 

Alpha-adrenergic syndrome. Hypertension with reflex bradycardia is characteristic of alpha-adrenergic syndrome. The pupils are usually dilated. (Examples phenylpropanolamine, phenylephrine, and methoxam-ine.)... 

The main limitation to the clinical use of the MAOIs is due to their interaction with amine-containing foods such as cheeses, red wine, beers (including non-alcoholic beers), fermented and processed meat products, yeast products, soya and some vegetables. Some proprietary medicines such as cold cures contain phenylpropanolamine, ephedrine, etc. and will also interact with MAOIs. Such an interaction (termed the "cheese effect"), is attributed to the dramatic rise in blood pressure due to the sudden release of noradrenaline from peripheral sympathetic terminals, an event due to the displacement of noradrenaline from its mtraneuronal vesicles by the primary amine (usually tyramine). Under normal circumstances, any dietary amines would be metabolized by MAO in the wall of the gastrointestinal tract, in the liver, platelets, etc. The occurrence of hypertensive crises, and occasionally strokes, therefore limited the use of the MAOIs, despite their proven clinical efficacy, to the treatment of atypical depression and occasionally panic disorder. 

Dangerous hypertensive reactions can result from interactions with the sympathicomimetic drugs isometheptene and phenylpropanolamine (SEDA-17,168). 

In one case the use of phenylpropanolamine with triple drug therapy for HIV prophylaxis led to a hypertensive crisis (44). As the patient had previously tolerated phenylpropanolamine well, one must suspect that one or more of the anti-HIV drugs (probably indinavir) had interfered with the metabolic breakdown of the phenylpropanolamine. 

Lee KY, Beilin LJ, Vandongen R. Severe hypertension after ingestion of an appetite suppressant (phenylpropanolamine) with indomethacin. Lancet 1979 1(8126) 1110-11. 

Monoamine oxidase inhibitors and many pharmacological agents are synergistic, sometimes resulting in a hypertensive crisis. The agents with which the MAOIs may be synergistic include amphetamine, dextroamphetamine, methyl amphetamine, ephedrine, procaine preparations (which usually contain norepinephrine), epinephrine, methyldopa, and phenylpropanolamine (over-the-counter cold preparations). 

Stress a-Adrenergic agonists Pseudoephedrine (15-60 mg three times a day) with food, water, or milk Pseudoephedrine is first-line therapy for women with no contraindication (notably hypertension) (second-line once duloxetine is approved) Phenylpropanolamine was the preferred agent until its removal from the U.S. market in 2000. 

OTC cold medications, or other medications that contain drugs with a, agonist activity (e.g., ephedrine, phenylpropanolamine), should be avoided with P antagonist therapy, as they may precipitate acute hypertension. This is due to the vasoconstrictor actions of the a agonist that are unopposed in the presence of a drug with P2 antagonist activity. 

Sympathomimetics (indirectly acting) Combining MAOis with agents such as amphetamines, cocaine, ephedrine, methylphenidate, pemoline, pseudoephedrine, phenylpropanolamine, and others (including many cold and allergy medications) can cause a potentially fatal hypertensive crisis. 

Accidental local infiltration of potent alpha agonists such as norepinephrine may lead to tissue ischemia and necrosis if not promptly reversed infiltration of the ischemic area with phentolamine is sometimes used to prevent tissue damage. Overdose with drugs of abuse such as amphetamine, cocaine, or phenylpropanolamine may lead to severe hypertension because of their indirect sympathomimetic actions. This hypertension will usually respond well to alpha-blockers. Sudden cessation of clonidine therapy leads to rebound hypertension (Chapter 11) this phenomenon is often treated with phentolamine. 

A. Hypertensive crisis associated with phenylpropanolamine or stimulant drug overdose (eg, amphetamines, cocaine, or ephedrine). 

Because of its weak MAO-inhibitory properties, the manufacturers of linezolid contraindicate its use with sympathomimetics (such as adrenergic bronchodilators, phenylpropanolamine, pseudoephedrine, adrenaline (epinephrine), noradrenaline (norepinephrine), dopamine and dobutamine) unless facilities for close observation and blood pressure monitoring are available. In one study the use of linezolid with phenylpropanolamine or pseudoephedrine resulted in additive hypertensive effects. 

The manufaeturers eontraindieate the use of sympathomimetics (including adrenergic bronchodilators, pseudoephedrine, phenylpropanolamine, adrenaline (epinephrine), noradrenaline (norepinephrine), dopamine, dob-utamine) with linezolid unless there are faeilities available for close observation of the patient and monitoring of blood pressure. Some indirectly-aeting sympathomimetics occur in cough and cold remedies, whieh can be bought without prescription. To keep in line with the manufaeturers recommendations, patients should be told to avoid these preparations. However, it should be said that the evidenee available indicates that blood pressure rises are unlikely to be of the proportions seen with the antidepressant MAOIs, which result in hypertensive crises. Consider also MAOIs or RIMAs + Sympathomimetics Indirectly-acting , p.l 147. 

A healthy postpartum woman taking bromocriptine developed very severe headache and marked hypertension after also taking phenylpropanolamine. Similarly another woman developed seizures with cerebral vasospasm, and a third developed a severe headache, hypertension and severe cardiac dysfunction after also taking isometheptene. A further patient taking bromocriptine developed psychosis when pseudoephedrine was added. 

Not understood. Severe hypertension occasionally occurs with either bromocriptine or phenylpropanolamine given alone. Shortly after giving birth some individuals show increased vascular reactivity, and it could be that all of these factors conspired together to cause these adverse effects. Psychosis occasionally occurs after giving birth or on bromocriptine alone, so that in the latter case the addition of pseudoephedrine may have been coincidental. ... 

O Connell MB, Gross CR. The effect of single-dose phenylpropanolamine on blood pressure inpatients with hypertension controlled by p blockers. Pharmacotherapy 1990 ) 10, 85-91. 

A man with renal hypertension, whose blood pressure was well controlled with methyidopa 250 mg twice daily and oxprenolol 160 mg three times daily, had a rise in blood pressure from under 140/80 mmHg to 200/150 mmHg within 2 days of starting to take two tablets of Triogesic (phenylpropanolamine 12.5 mg and paracetamol 500 mg) three times daily. His blood pressure fell when the Triogesic was withdrawn. ... 

Direct information seems to be limited to these reports. They suggest that an adverse hypertensive response is unlikely in most individuals given these drugs. However, note that phenylpropanolamine alone has been associated with severe hypertension and has been implicated in causing stroke. It is therefore no longer available in the US and UK and its use has been restricted in many other countries. 

Phenylpropanolamine can raise blood pressure and in some cases this may be further increased by caffeine. Combined use has resulted in hypertensive crises in a few individuals. Ephedrine may interact similarly. Phenylpropanolamine can markedly raise plasma caffeine levels, and isolated reports describe the development of acute psychosis when caffeine was given with phenylpropanolamine or ephedrine. 

Sympathomimetic drugs Reversible hypertension has been observed in patients taking hnezohd with sjmipathomunetic drugs, such as pseudoephedrine and phenylpropanolamine [175. ... 

McLaren, E. H. (1976) Severe hypertension produced by interaction of phenylpropanolamine with methyldopa and oxprenolol. Brit. med. J 2, 283. 

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