Hypertension sympathomimetics

A-R ligand (> 10) (DNAP) (3A-R agonist (a2A-R) [vasoconstrictive, hypertensive, sympathomimetic hormone]... 

CENTRALLY ACTING ANTI HYPERTENSIVES SYMPATHOMIMETICS-DIRECT Risk of t BP when donidine is given with epinephrine or norepinephrine Additive effect donidine use associated with t circulating catecholamines Monitor BP at least weekly until stable... 

CENTRALLY ACTING ANTI HYPERTENSIVES SYMPATHOMIMETICS-INDIRECT 1. Indirect sympathomimetics may i the hypotensive effect of methyldopa 2. Methyldopa may 1 the mydriatic effect of ephedrine eye drops 1. Uncertain 2. Uncertain 1. Monitor BP at least weekly until stable 2. Watch for a poor response to ephedrine eye drops... 

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. 

P-Adrenoceptor blockers for the treatment of hypertension include (/) the cardioselective P -adrenoceptor blockers without intrinsic sympathomimetic activity (ISA), ie, atenolol (Table 3), bisoprolol (Table 3), and metoprolol (Table 1) (2) the cardioselective with ISA, ie, acebutolol (Table 1) (J) the noncardioselective without ISA, ie, propranolol (Table 1) and timolol [26839-75-8] C23H24N4O2S and (4) the noncardioselective with ISA, ie, oxprenolol [6452-71-7] C 3H23N03, and pindolol. 

Hypertensive reaction resulting from release of noradrenaline by tyramine and other sympathomimetic amine as a consequence of irreversible inhibition of MAO-A. 

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. 

Older adults, in particular, are at risk for exacerbation of existing disorders such as hypertension, tachycardia, or arrhythmias if systemic absorption of sympathomimetic ophthalmic drugs occurs... 

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. 

Thus the "ideal" anti-hypertensive 3-blocking agent should be a moderately long acting cardioselective agent showing little or no intrinsic sympathomimetic activity. 

Figure 27. Comparison of the relationship between antihypertensive and sympathomimetic activity and sedation and inhibition of gastric secretion of clonidine and two derivatives (St 600 and St 608). The antihypertensive activity was tested in genetic hypertensive rats. The sympathomimetic activity was measured as blood pressure increase in spinal rats. The sleep effect in chicks was tested according to the method in Reference 50, and the gastric secretion in rats was measured according to the method in Reference 57.

Psilocybe intoxication is very similar to other monoamine hallucinogens in terms of the subjective and hallucinogenic effects. Similar to other monoamine hallucinogens, psilocybe mushroom intoxication produces sympathomimetic features of tachycardia, hypertension, and hyperreflexia (Peden et al. 1982). Many experience nausea and vomiting. Perceptual distortions are primarily visual, but paresthesia and feelings of depersonalization also occur. The acute effects of psilocybe intoxication are shorter-lived than LSD, typically lasting 4-6 hours and completely clearing by 12 hours. 

Predictable interactions occur between the MAOIs and any amine precursors, or directly or indirectly acting sympathomimetic amines (e.g. the amphetamines, phenylephrine and tyramine). Such interactions can cause pronounced hypertension and, in extreme cases, stroke. 

Phenylephrine is a nasal decongestant that mimics the sympathetic system, thereby increasing the heart rate and blood pressure. It may aggravate conditions such as diabetes, hypertension and glaucoma. Patients with hypertension, ischaemic heart disease, hyperthyroidism, diabetes and glaucoma are therefore given topical nasal sympathomimetics rather than systemic sympathomimetics. Both topical and systemic sympathomimetics are contraindicated in patients taking monoamine oxidase inhibitors, because concurrent administration of the two products may lead to a hypertensive crisis. 

Sympathomimetics mimic the sympathetic system, thereby increasing the force of contraction of the heart and the blood pressure. Sympathomimetics are therefore contraindicated in patients with hypertension. Oral rehydration salts consist of electrolytes including sodium and therefore should be used with care. The advantages of oral rehydration salts in diarrhoea outweigh this disadvantage. 

Advanced arteriosclerosis symptomatic cardiovascular disease moderate to severe hypertension hyperthyroidism hypersensitivity or idiosyncrasy to the sympathomimetic amines glaucoma agitated states history of drug abuse during or within 14 days following administration of monoamine oxidase (MAO) inhibitors (hypertensive crises may result). 

Hypertension or heart disease Use with caution since dronabinol may cause a general increase in central sympathomimetic activity. 

Uses Postpartum bleeding (uterine subinvolution) Action Ergotamine derivative Dose 0.2 mg IM after placental deliv y, may repeat 2-4-h intervals or 0.2-0.4 mg PO q6-12h for 2-7 d Caution [C, ] Contra HTN, PRO Disp Inj, tabs SE HTN, N/V Interactions t Vasoconstriction W/ ergot alkaloids, sympathomimetics, tobacco EMS Tobacco use can t vasoconstriction and lead to a hypertensive crisis OD May cause N/V/D, chest/abd pain, limb numbness, and possibly distal gangrene d/t vasoconstriction activated charcoal may be effective for PO form... 

Due to the numerous indications for these type of drugs a large number of compounds have been introduced into therapy. Differences between these drugs concern their affinity profile towards the Pi-and j82-adrenoceptors, the lipophilicity and the ability to partially activate the receptor (intrinsic sympathomimetic activity, ISA). One isomer of the racemic mixture of labetalol and carvedilol are a-blocker as well. Although this might be therapeutically useful in the treatment of conditions like hypertension and heart failure, there is no real evidence for a contribution of this property to the overall beneficial effect of these compounds. 

Pindolol, oxprenolol, acebutolol and alprenolol are /3-blocker ISA. A weak sympathomimetic effect can be seen in the heart if almost all /3-adrenoceptors are occupied by these compounds. The advantage of ISA might be that a basal /3-adrenergic stimulus is left. In some vessel beds a reduction of the vascular activity and thereby a reduction in resistance has been observed with pindolol which might be beneficial in the therapy of hypertension. The pharmacodynamic and -kinetic properties of some frequently used jS-blocker are shown in Table 2. 

---