Drug Name Paxil

This fact assumes practical significance with any drug that may be rapidly transformed or possibly inactivated in the liver (first-pass hepatic elimination). Even with rectal administration, at least a fraction of the drug enters the general circulation via the portal vein, because only veins draining the short terminal segment of the rectum communicate directly with the inferior vena cava.
The latter are embryologic homologues of ganglionic sympathocytes. Excitation of preganglionic fibers leads to release of ACh in the adrenal medulla, whose chromaffin cells then respond with a release of epinephrine into the blood (D). Small doses of nicotine, by inducing a partial depolarization of adrenomedullary cells, are effective in liberating epinephrine.

 

Abrupt termination of continuous treatment can be followed by rebound hypertension (particularly with short t1/2 ?-blockers). Drugs for the control of hypertensive crises include nifedipine (capsule, to be chewed and swallowed), nitroglycerin (sublingually), clonidine (p. o. or i. v. , p. 96), dihydralazine (i. v. ), diazoxide (i. v. ), fenoldopam (by infusion) and sodium nitroprusside.
Immune responses can occur without appropriate cause or with exaggerated intensity and may harm the organism, for instance, when allergic reactions are caused by drugs. Only a few drugs, e. g. (heterologous) proteins, have a molecular mass (> 10,000) large enough to act as effective antigens or immunogens, capable by themselves of initiating an immune response.