Diafen - General Information

Diafen is an antihistamine. Antihistamines used in the treatment of allergy act by competing with histamine for H 1-receptor sites on effector cells. Antihistamines prevent, but do not reverse, responses mediated by histamine alone. Antihistamines antagonize, in varying degrees, most of the pharmacological effects of histamine, including urticaria and pruritus.


Pharmacology of Diafen

Diafen is an antihistamine that prevents, but does not reverse, responses mediated by histamine alone. Diafen antagonizes most of the pharmacological effects of histamine, including urticaria and pruritus. Also, diphenylpyraline may exhibit anticholinergic actions (as do most of the antihistamines) and may thus provide a drying effect on the nasal mucosa.


Diafen for patients

Take with food, water, or milk to minimize gastric irritation. Swallow the extended-release dosage form whole (do not crush). If you miss a dose, take as soon as possible but do not take if it is almost time for your next dose. DO NOT double up on doses. Notify your doctor if skin tests using allergens is required as this medication may interfere with test results. Avoid use of alcohol or other CNS depressants while taking this medication. This medication can cause drowsiness or dizziness. Use caution while taking this medicine when driving or using equipment. Talk to your doctor if you are taking appetite suppressants. This medication can cause insomnia. Take the medication a few hours before bedtime if this occurs. This medication can cause dryness of mouth - use sugarless gum, candy, ice, or saliva substitute for relief. Check with your dentist if dry mouth continues for more than 2 weeks.


Diafen Interactions

This drug may interact with alcohol or other CNS depressants (may potentiate the CNS depressant effects of either these medications or antihistamines), anticholinergics or other medications with anticholinergic activity (anticholinergic effects may be potentiated when these medications are used concurrently with antihistamines), and monoamine oxidase (MAO) inhibitors (concurrent use with antihistamines may prolong and intensify the anticholinergic and CNS depressant effects of antihistamines).


Diafen Contraindications

Contraindicated in the following: blood disease, heart or blood vessel disease (may cause more serious conditions to develop), enlarged prostate, urinary tract blockage or difficult urination (antihistamines may cause urinary problems to become worse), epilepsy (antihistamines may increase the chance of seizures), glaucoma (may cause a slight increase in inner eye pressure that may worsen the condition, jaundice (antihistamines may make the condition worse), liver disease (antihistamines may build up in the body, which may increase the chance of side effects such as muscle spasms), Reye's syndrome (antihistamines may increase the chance of uncontrolled movements).


Additional information about Diafen

Diafen Indication: For use in the treatment of allergic rhinitis, hay fever, and allergic skin disorders.
Mechanism Of Action: Antihistamines such as diphenylpyraline used in the treatment of allergy act by competing with histamine for H1-receptor sites on effector cells. This reduces the effects of histamine, leading to a temporary reduction of allergy symptoms.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Diphenylpyraline
Synonyms: Diphenylpyralamine; Diphenylpyraline Hydrochloride; Diphenylpyrilene
Drug Category: Antihistamines
Drug Type: Small Molecule; Approved

Other Brand Names containing Diphenylpyraline: Allergen; Belfene; Dafen; Dayfen; Diafen; Hispril; Histryl; Histyn; Hystryl; Lyssipoll; Mepiben; Neargal;
Absorption: Well absorbed after oral administration.
Toxicity (Overdose): Not Available
Protein Binding: > 99% in human serum albumin
Biotransformation: Hepatic
Half Life: Not Available
Dosage Forms of Diafen: Liquid Intradermal
Liquid Subcutaneous
Chemical IUPAC Name: 4-[di(phenyl)methoxy]-1-methylpiperidine
Chemical Formula: C19H23NO
Diphenylpyraline on Wikipedia:
Organisms Affected: Humans and other mammals