diphenhydramine
Download
Skip this Video
Download Presentation
Diphenhydramine

Loading in 2 Seconds...

play fullscreen
1 / 23

Diphenhydramine - PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on

Diphenhydramine. Banan Muneer Laboum Wala ’ Fayez Sabateen. Pharmacology. Antihistamine with anti cholinergic properties Antitussive, anti emetic and local anesthetic properties. Antihistaminic (H1)property Relief itching and irritation caused by :

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Diphenhydramine' - ryan-torres


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
diphenhydramine

Diphenhydramine

Banan MuneerLaboum

Wala’ Fayez Sabateen

pharmacology
Pharmacology

Antihistamine with anti cholinergic properties

Antitussive, anti emetic and local anesthetic properties

slide3

Antihistaminic (H1)propertyRelief itching and irritation caused by :

Plant induced dermatitis

Insect bites

Animal serum antivenoms or anti toxin

( anaphylaxis)

slide4

Antichoilergic property controlling

drug-induced extrapyramidal symptoms

pharmacokinetics
Pharmacokinetics

Maximal effects are at 1 hour after IV injection and lasts up to 7 hours

Serum half-life is 3-7 hours

Hepatic elimination

indications
Indications:

Pruritus caused by poison oak , poison ivy or minor insect bites

Pretreatment before administration of animal serum antivenoms or antitoxins, esp. in patients with a history of hypersensitivity or with positive skin test

slide7

Relief of symptoms caused by excessive histamine effects:

Scombroid – contaminated fish ingestion

Niacin

Rapid IV administration of

acetylcysteine

slide8

Neuroleptic drug-induced extrapyramidal symptoms and priapism

Eg. of these drugs :

Haloperidol, Phenothiazines, Clozapine

Alteration in the normal balance between central acetylcholine and dopamine transmission

slide9

Metoclopramide induced tardive dyskinesia:

Blocks dopamine receptors in CTZ

  Sensitizes tissues to acetylcholine

contraindications
Contraindications

Prostatic hypertrophy with obstructive uropathy

Angel- closure glaucoma

Concurrent therapy with MAOI

adverse effects
Adverse effects
  • Sedation, drowsiness, and ataxia may occur.
  • Paradoxicexcitation is possible in small children.
  • Excessive doses may cause:
  • Flushing, tachycardia, blurred vision, delirium, toxic psychosis, urinary retention, and respiratory depression.
slide12

Some preparations may contain sulfite preservatives  allergic-type reactions in susceptible persons.

  • Extravasation from an IV admin. chronic regional pain syndrome.
  • Local necrosis from subcutaneous route.
slide13

Use in pregnancy:

  • FDA category B.
  • Fetal harm is extremely unlikely.
drug or lab interactions
Drug or lab. interactions
  • Opioids, ethanol, and other sedatives
  • Additive sedative effect.
  • Other antimuscarinicdrugs
  • Additive anticholinergic effect.
dosage and method of administration
Dosage and method of administration

Pruritus:

  • Adult:

-- 25-50 mg PO q. 4-6 hrs, max. daily dose is 300 mg.

  • Children, 5 mg/kg/day in divided doses:
  • Ages 2 to 6 years:

-- 6.25 mg q. 4-6 hrs, max. daily dose is 37.5 mg

  • Ages 6-12 yrs:

12.5 to 25 mg PO q. 4-6 hrs, max. daily dose 150mg.

slide16

The drug may also be applied topically.

  • Systemic absorption and toxicity have been reported, especially when used on large areas with blistered or broken skin.
slide17

Pretreatment before antivenom administration:

  • Adult : 50 mg IV

Children: 0.5-1 mg/kg IV

  • If possible, it should be given at least 15-20 min. before antivenom use.
  • Rate of IV admin. should not exceed 25 mg/min.
slide18

Drug-induced extrapyramidal symptoms:

  • Adult :50 mg

Children, 0.5-1 mg/kg

  • IV at a rate not to exceed 25 mg/min, or deep IM
  • If there is no response within 30-60 min.

 Repeat dose to a maximum 100 mg (adults).

slide19

Provide oral maintenance therapy to prevent recurrence:

  • Adult : 25-50 mg q. 4-6 hrs for 2-3 days

Maxi. daily dose 400 mg.

  • Children (0.5-1 mg/kg):
  • If < 9 kg  6.25 to 12.5 mg q. 4-6 hrs for 2-3 days
  • If > 9 kg  12.5 to 25-mgq. 4-6 hrs for 2-3 days
  • Maxi. daily dose, 300 mg
formulations
Formulations

Oral:

  • Diphenhydramine hydrochloride (Benadryl)
  • Tablets and capsules --- 25 mg and 50 mg.
  • Chewable tablets --- 12.5 mg.
  • Elixir, syrup, and oral solution --- 12.5 mg/5 mL.
slide21

Parenteral:

  • Diphenhydramine hydrochloride (Benadryl)
  • 50 mg/mL in 1-mL cartridges, amps, steri-vials, and syringes
  • 50 mg/ml in 10-mL steri-vials (may contain benzethonium chloride).
slide22

The suggested minimum stocking level to treat a 70-kg adult for the first 24 hours is:

  • One vial (50 mg/mL, 10 mL each)
  • Or eight vials (50 mg/mL, 1 mL each).