Autacoids in which u learn about histamine and antihistamines

1. Autacoids
• Autacoids are substances formed in varioustissues,
have complex physiologic andpathologic actions
and act locally at the siteof synthesis.
• They have a brief action andare destroyed locally.
Hence they are called‘local hormones’ and differ
from truehormones.
• . The word autacoid is derived from Greek: autos =
self akos = remedy

2. Autacoids Include
• Histamine,
• 5-hydroxytryptamine
• Angiotensin,
• kinins,
• Prostaglandins,
• leukotrienes,
• platelet activating factor.

4. HISTAMINE
Histamine or tissue amine (Histos = tissue) is
a biogenic amine formed in many tissues. It
is also found in the venoms of bees, wasps
and other stinging secretions.

7. Antihistamines,

8. Classification
• Di-phen-hydra-mine, (20-50 mg oral,IM.,)
• Pro-metha-zine (20-25 mg oral, IM )
1. Sedative
2. Non - sedative
• Phenira-mine(25-50 mg oral, IM )
• Chlor-phenira-mine ( 4-20 mg oral, IM )
• Cycli-zine (50 mg oral)
3.newer non sedative ( 2nd generation agent)
• Citrizine(10mg oral)
• Tera-fena-dine
• Fexo-fena-dine