Sympathomimetics adverse effects

In terms of comparative adverse effects, imipramine produces more dry mouth than reboxetine probably because imipramine blocks muscarinic cholinergic receptors as well as inhibiting NE uptake (47,5). Imipramine also produces more tremulousness and hypotension than reboxetine. Consistent with their pharmacology, fluoxetine produces more serotonin-mediated adverse effects than does reboxetine (i.e., nausea, loose stools, and somnolence), whereas reboxetine causes more sympathomimetic adverse effects (476). To date, reboxetine has not been reported to cause an increased incidence of laboratory abnormalities. 

A warning was issued by the Swiss Pharmaceutical Association that phenylpropanolamine can cause severe sympathomimetic adverse effects, including hypertensive... 

Decongestants such as OTC pseudoephedrine are sympathomimetic agents that constrict capacitance vessels in the nasal turbinates.17 Decongestants effectively reduce nasal congestion and to some extent rhinorrhea associated with AR.8,12 The recommended dose of pseudoephedrine is 30 to 60 mg every 4 to 6 hours for a maximum daily dose of 240 mg.15 Systemic adverse effects such as irritability, dizziness, headache, tremor, tachycardia, and insomnia can occur. Additionally, use is associated with increased blood pressure and intraocular pressure and urinary obstruction.8,12... 

Pseudoephedrine (Sudafed, Novafed, Afrinol, Others) [OTC] [Decongestant/Sympothomimetic] Uses Deconge tant Action Stimulates a-adren gic rec tors w/ vasoconstriction Dose Adults. 30-60 mg PO q6—8h Peds. 4 mg/kg/24 h PO qid -1- in renal insuff Caution [C, +] Contra Poorly controlled HTN or CAD, w/MAOIs Disp Tabs, caps, Liq SE HTN, insomnia, tach, arrhythmias, nervousness, tremor Interactions T Risk of HTN crisis W/ MAOIs T effects W/BBs, sympathomimetics X effects W/TCAs -1- effect OF methyldopa, reserpine EMS Found in many OTC cough/cold pr >arations use sympathomimetics w/ caution, may T adverse effects OD May cause N/V, HTN, arrhythmias, and Szs symptomatic and supportive... 

As with most data for reboxetine, this information primarily comes from summary papers rather than primary sources (473, 474). With this caveat, the adverse-effect profile of reboxetine is consistent with its pharmacology as an NSRI. Thus, it is similar to that of desipramine and maprotiline but without the risk of serious CNS (i.e., seizures, delirium) or cardiac (i.e., conduction disturbances) toxicity. The most common adverse effects of reboxetine are dry mouth, constipation, urinary hesitancy, increased sweating, insomnia, tachycardia, and vertigo. Whereas the first three adverse effects are commonly called anticholinergic, they are well known to occur with sympathomimetic drugs as well. In other words, these effects can be either the result of decreased cholinergic tone or increased sympathetic tone, although they tend to be more severe with the former than the latter. In contrast to TCAs, reboxetine does not directly interfere with intracardiac conduction. The tachycardia produced by reboxetine, however, can be associated with occasional atrial or ventricular ectopic beats in elderly patients. 

Despite impressions to the contrary, MAOIs are generally well tolerated if patients observe the restricted diet and avoid medications that contain sympathomimetic amines. Adverse effects are rarely a treatment-limiting problem with the exception of hypotension. MAOIs also fall between TCAs and SSRIs in terms of overdose risk. Major toxic reactions to MAOIs are uncommon but require immediate discontinuation and symptomatic treatment. 

The antimuscarinic properties result in what are usually the most troublesome adverse effects dry mouth, blurred vision, constipation, and (mainly in older males) urinary hesitancy and retention. Pupil size, and hence risk of glaucoma, is determined by a balance between anticholinergic (mydriatic) and sympathomimetic (miotic) effects. 

Adrenoceptors are distributed in virtually all organ systems. This section focuses on the activation of adrenoceptors that are responsible for the therapeutic effects of sympathomimetics or that explain their adverse effects. A more detailed description of the therapeutic use of sympathomimetics is given later in this chapter. 

One of the most important uses of sympathomimetic drugs is in the therapy of bronchial asthma. This use is discussed in Chapter 20. Nonselective drugs (epinephrine), -selective agents (isoproterenol), and B2-selective agents (albuterol, metaproterenol, terbutaline) all are available for this indication. Sympathomimetics other than the 32-selective drugs are now rarely used because they are likely to have more adverse effects than the selective drugs. 

MAOIs interact with sympathomimetics, barbiturates, hypoglycemics, antimus-carinics, alcohol, antihypertensives, and antidepressants. Care must be exercised during concomitant administration. Since adverse effects may be seen after a long period, patients must be monitored carefully, even after therapy.144... 

Moclobemide increased the pressor effect of ephedrine in healthy volunteers, who also had more adverse effects including light-headedness and palpitation (SEDA-18, 16). Thus, moclobemide can potentiate the effect of indirect sympathomimetics such combinations should be used with caution. 

The anorectic agents produce adverse effects mainly of the central nervous system sympathomimetic type. Therapy should therefore only be allowed under strict medical supervision, to ensure the earliest possible detection of any signs of drug abuse. Long-term drug treatment of obesity should be avoided altogether. 

SYMPATHOMIMETICS H2 RECEPTOR BLOCKERS t efficacy and adverse effects of sympathomimetics Unclear t hypertensive response dose reduction may be required. Monitor ECG for tachycardias... 

Phenmetrazine and phendimetrazine are central stimulants and indirect sympathomimetics related to dexamfetamine. Phendimetrazine is about 30% rapidly metabolized to phenmetrazine (1). Their reported adverse effects include glossitis, stomatitis, dry mouth, nausea, abdominal pain, cramps, constipation, difficulty in micturition, and headache. 

The expected cardiovascular stability of vecuronium has been confirmed in man (2,21-23). Even doses as large as 0.28 mg/kg in patients undergoing coronary artery bypass grafting produced negligible effects (24). Bradycardia is the only cardiovascular adverse effect reported, and this is seen in association with opioids such as fentanyl (25) and sufentanil (SEDA-11, 125) (26) or other drugs that are themselves capable of producing bradycardia. The lack of vagolytic and sympathomimetic activity of vecuronium... 

The adverse effects of amphetamine and related sympathomimetic appetite suppressants are well documented. All of these agents are classified by the U.S. Drug Enforcement Administration (DEA) as controlled substances (classes II-IV) according to their potential for causing addiction (see Table 15.4). Class II agents such as amphetamine are highly abused, with prescription restricted to speeial circumstances class TV anorectic drugs such as sibutramine, phentermine, di-ethylpropion, and mazindol have minimal abuse potential. 

Sympathomimetics are available in inhaled, oral, and parenteral dosage forms. The preferred route of administration is by inhalation. The use of oral and parenteral /3-agonists in COPD is discouraged because they are no more effective than a properly used metered-dose inhaler (MDI) or dry-powder inhaler (DPI), and the incidence of systemic adverse effects such as tachycardia and hand tremor is greater. Administration of /32-agonists in the outpatient and emergency room settings via inhalers (MDIs or DPIs) is at least as effective as nebulization therapy and usually favored for reasons of cost and... 

Esmolol (Brevibloc, others) is a Pi-selective antagonist with a very short duration of action. It has little if any intrinsic sympathomimetic activity, and it lacks membrane-stabilizing actions. Esmolol is administered intravenonsly and is nsed when P-blockade of short dnration is desired, or in critically ill patients in whom adverse effects of bradycardia, heart failure, or hypotension may necessitate rapid withdrawal of the drug. 

In the treatment of hypertension, a major use of beta-blockers is in combination with hydralazine. The direct vasodilators bring about reflex cardiac stimulation, and beta-blockers prevent these adverse effects (see also Figure 67). Beta-blockers also reduce blood pressure by exerting a central effect or a peripheral action, or both, which decreases renin activity. Metoprolol and atenolol are beta selective, and they are safer agents in patients with asthma, diabetes mellitus, or low-renin hypertension. Some beta-blocking agents such as pindolol have intrinsic sympathomimetic activity and may be used in the treatment of pronounced bradycardia (sick sinus syndrome). Unlike propranolol, metoprolol is not a very lipid-soluble... 

PULMONARY FUNCTION A major adverse effect of P receptor antagonists is the bronch-constriction resulting from blockade of receptors in bronchial smooth muscle. P Blockers may cause a life-threatening increase in airway resistance in patients with bronchospastic disease. 3j-selective antagonists or those with intrinsic sympathomimetic activity at adrenergic receptors may be somewhat less likely to induce bronchospasm however, the selectivity of current p blockers is modest, and these drugs should be avoided if possible in patients with asthma. 

ADVERSE EFFECTS Dronabinol has complex effects on the CNS, including a prominent central sympathomimetic activity that can lead to palpitations, tachycardia, vasodilation, hypotension, and conjunctival injection (bloodshot eyes). Patient supervision is necessary because marijuana-hke highs e.g., euphoria, somnolence, detachment, dizziness, anxiety, nervousness, panic, etc.) can occur, as can more disturbing effects such as paranoid reactions and thinking abnormalities. After abrupt withdrawal of dronabinol, an abstinence syndrome manifest by irritability, insomnia, and restlessness can occur. Because of its high affinity for plasma proteins, dronabinol can displace other plasma protein-bound drugs, whose doses may have to be adjusted as a consequence. Dronabinol should be prescribed with great caution to persons with a history of substance abuse because it also may be abused by these patients. 

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