Ai -antagonists

Individual vasodilators. Nitrates (p. 120) Ca -antagonists (p. 122). ai-antagonists (p. 90), ACE-inhibitors, ATI -antagonists (p. 124) and sodium nitro-prusside (p. 120) are discussed elsewhere. 

Simple tertiary amines can be grafted to a carbon skeleton, either by exchange reactions or by Mannich reactions. The hydrochloride salt of the camptothecin derivative (a) (Figure 38.15) is soluble in water at concentrations up to 1 mg/mL the comparable value for camptothecin itself is 0.0025 mg/mL. Similar results were obtained in solubilizing the benzodiazepine (b) and the quinazolinone (c). The adenosine Ai antagonist KW-3902 (d) was solubilized in an original manner by converting it to an amidinic and cyclized bioisostere (e). ... 

Drugs that are used to treat hypertension include diuretics, ACE inhibitors, angiotensin 11 receptor antagonists, P-blockers, calcium channel blockers, ai-antagonists and centrally acting antihypertensives. 

While class 1 calcium channel blockers are used to treat atrial arrhythmia, class II and class 111 calcium channel blockers are now considered first-line therapy for many patients with hypertension. Resistant hypertension can be treated with add-on drugs ai-antagonists, centrally acting antihypertensives and adrenergic neurone blockers. 

The 5a-reductase inhibitors work by suppressing the production of intraprostatic DHT, thereby reducing the size of the prostate (90). Finasteride and dutasteride are the most commonly used drugs for this purpose. Unlike ai-antagonists, 5a-reductase inhibitors are able to reverse BPH to some extent and so may delay the need for surgery. Several months of treatment may be needed before the benefit is noticed. 

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