(±)-Pheniramine

240.34

240.34

201-656-2

47965

DTXSID0023454

D - Dermatologicals|R - Respiratory system

2933399090

16.1

3.16520

Solid

1.0081 g/cm³

<25 °C

181 °C

9℃

1.556

3.77e-01 g/L

-20°C

III

8

UN1230 - class 3 - PG 2 - Methanol, solution

3

11-23/24/25-39/23/24/25

16-36/37-45

F,T

P210-P260-P280-P301 + P310-P311

H225-H301 + H311 + H331-H370

|Danger|H300 (97.44%): Fatal if swallowed [Danger Acute toxicity, oral]|P264, P270, P301+P310, P321, P330, P405, and P501|Aggregated GHS information provided by 39 companies from 2 notifications to the ECHA C&L Inventory.

Case reports involving pheniramine overdosage mention the rare possibility of arrythmias, cutaneous eruptions, and rhabdomyolysis with acute kidney injury. The administration of activated charcoal effectively prevents the absorption of pheniramine as it largely adsorbs to the charcoal, therefore this may be of benefit in cases of overdose if provided early after ingestion.

Pheniramine is commonly used in over-the-counter products to treat seasonal allergies or cold and flu symptoms.|FDA Label

Pheniramine has known transformation products that include N-Desmethylpheniramine and Pheniramine-N-oxide.

Pheniramine acts as an antagonist to allergic symptoms stemming from inappropriate histamine release to reduce edema, itching, and redness. The same antihistamine effect also produces sedation by acting in the central nervous system.

Drugs that selectively bind to but do not activate histamine H1 receptors, thereby blocking the actions of endogenous histamine. Included here are the classical antihistaminics that antagonize or prevent the action of histamine mainly in immediate hypersensitivity. They act in the bronchi, capillaries, and some other smooth muscles, and are used to prevent or allay motion sickness, seasonal rhinitis, and allergic dermatitis and to induce somnolence. The effects of blocking central nervous system H1 receptors are not as well understood. (See all compounds classified as Histamine H1 Antagonists.)|Agents that are used to treat allergic reactions. Most of these drugs act by preventing the release of inflammatory mediators or inhibiting the actions of released mediators on their target cells. (From AMA Drug Evaluations Annual, 1994, p475) (See all compounds classified as Anti-Allergic Agents.)|Agents, usually topical, that relieve itching (pruritus). (See all compounds classified as Antipruritics.)

The administration of 30.5 mg of free base pheniramine resulted in a Cmax of 173-294 ng/L with a Tmax of 1-2.5 h.|Pheniramine is eliminated by metabolism and via renal excretion. 24.3% of pheniramine is present in the urine as the parent drug.

Pheniramine undergoes N-dealkylation to N-didesmethylpheniramine and N-desmethylpheniramine.

The terminal half-life of pheniramine administered via IV is 8-17 h.

Pheniramine competes with histamine for the histamine H1 receptor, acting as an inverse agonist once bound. The reduction in H1 receptor activity is responsible for reduced itching as well as reduced vasodilation and capillary leakage leading to less redness and edema. This can be seen in the suppression of the histamine-induced wheal (swelling) and flare (vasodilation) response. Inverse agonism of the H1 receptor in the CNS is also responsible for the sedation produced by first-generation antihistamines like pheniramine. The binding of pheniramine to H4 receptors, and subsequent inverse agonism, may also contribute to reduced itching by antagonizing inflammation.

Avil

Human Drugs -> FDA Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book) -> Active Ingredients|Pharmaceuticals -> Animal Drugs -> Approved in Taiwan|Pharmaceuticals -> Dermatologicals -> Antihistamines