Itraconazole:

The drug may be given orally or intravenously.

Sympatholytics (Antiadrenergic Agents)

PHENOXYBENZAMINE
It is a potent alpha-adrenergic blocking agent 

It effectively prevents the responses mediated by alpha receptors and diastolic blood pressure tends to decrease.
It interferes with the reflex adjustment of blood pressure and produces postural hypotension. 
It increases the cardiac output and decreases the total peripheral resistance.

It is used in the management of pheochromocytoma and also to treat peripheral vasospastic conditions e.g. Raynaud’s disease and shock syndrome.

Phentolamine, another alpha blocker is exclusively used for the diagnosis of pheochromocytoma and for the prevention of abrupt rise in blood pressure during surgical removal of adrenal medulla tumors.

ERGOT ALKALOIDS

 Ergotamine is an  important alkaloid that possesses both vasoconstrictor and alpha-receptor blocking activity. Both ergotamine and dihydroergotamine are used in the treatment of migraine.

METHYSERGIDE

It is a 5-hydroxytryptamine antagonist ). It is effective in preventing an attack of migraine. 

SUMATRIPTAN

It is a potent selective 5-HT 1D  receptor agonist used in the treatment of migraine.

PRAZOSIN
It is an piperazinyl quinazoline effective in the management of hypertension. It is highly selective for α1  receptors. It also reduces the venous return and cardiac output. It is used in essential hypertension, benign prostatic hypertrophy and in Raynaud’s syndrome.
Prazosin lowers blood pressure in human beings by relaxing both veins and resistance vessels but it dilates arterioles more than veins.

TERAZOSIN
It is similar to prazosin but has higher bioavailability and longer plasma t½

DOXAZOSIN
It is another potent and selective α1 adrenoceptor antagonist and quinazoline derivative.
It’s antihypertensive effect is produced by a reduction in smooth muscle tone of peripheral vascular beds.

TAMSULOSIN
It is uroselective α1A  blocker and has been found effective in improving BPH symptoms.

Other drugs used for erectile dysfunction

Sildenafil: It is orally active selective inhibitor of phosphodiesterase type 5 useful in treatment of erectile dysfunction.

Agonist, Antagonist, and Partial Agonists

Agonists:  molecules that activate receptors.  A drug that mimics the body's own regulatory processes.
Antagonists:  produce their effects by preventing receptors activation by endogenous regulatory molecules and drugs.  Block activation of receptors by agonists.
Noncompetive Antagonist:  Bind irreversibly to receptors, and reduce the maximal response that an agonist can elicit.
Competitive Antagonist:  Bind reversibly to receptors, competing with agonists for binding sites.
Partial Agonists:  Have moderate intrinsic activity, the maximal effect that a partial agonist can produce is lower than that of a full agonist.  Act as antagonists as well as agonists.
 

EPHEDRINE

It act indirectly and directly on α and β receptors. It increases blood pressure both by peripheral vasoconstriction and by increasing the cardiac output. Ephedrine also relaxes the bronchial smooth muscles.

Ephedrine stimulates CNS and produces restlessness, insomnia, anxiety and tremors.
Ephedrine produces mydriasis on local as well as systemic administration.
Ephedrine is useful for the treatment of chronic and moderate type of bronchial asthma, used as nasal decongestant and as a mydriatic without cycloplegia. It is also useful in preventing ventricular asystole in Stokes Adams syndrome.

Midazolam -Intravenous Anesthetics
 Midazolam is a benzodiazepine used for preoperative sedation, induction of anesthesia, or maintenance of anesthesia in short procedures.

Sympatholytics And Alpha Adrenergic Blockers 

Types 
1.    Alpha 1-receptor blockers: prazocin,doxazocin. 
2.    Centrally acting alpha 2- agonists: methyldopa, clonidine. 
3.    Peripherally acting adrenergic antagonists: reserpine. 
4.    Imidazoline receptor agonists: rilmenidine, moxonidine. 
 
Advantages 

- Alpha1- receptor blockers and imidazoline receptor agonists improve lipid profile and insulin sensitivity. 
- Methyldopa: increases renal blood flow. Drug of choice during pregnancy. 
- Reserpine: neutral metabolic effects and cheap. 

Indications: 

- Diabetes mellitus: alpha1- receptor blockers, imidazoline receptor agonists. 
- Dyslipidemia: alpha 1- receptor blockers, imidazoline receptor agonists. 
- Prostatic hypertrophy: alpha 1- receptor blockers. 
- When there is a need for rapid reduction in blood pressure: clonidine. 

Side Effects 

- Prazocin: postural hypotension, diarrhea, occasional tachycardia, and tolerance (due to fluid retention). 
- Methyldopa: sedation, hepatotoxicity, hemolytic anemia, and tolerance. 
- Reserpine: depression, lethargy, weight loss, peptic ulcer, diarrhea, and impotence
- Clonidine: dry mouth, sedation, bradycardia, impotence, and rebound hypertension if stopped suddenly. 

Considerations 
- Prazocin, methyldopa, and reserpine should be combined with a diuretic because of fluid retention. 

Direct Arterial Vasodilators 

Types: hydralazine, diazoxide, nitroprusside, and minoxidil