Ketotifen

Registered South African indications:

• Long term prevention of asthma
• Allergic skin reactions
• Allergic rhinitis

Contraindications

• Hypersensitivity to the active ingredient or any of its excipients
• Pregnancy
• Breastfeeding
• Hepatic impairment

Cautions

• Renal impairment
• Elderly
• Porphyria
• History of epilepsy
• Intake with alcohol
• Abrupt withdrawal of other anti-allergic agents
• Abrupt withdrawal of anti-asthmatic agents (especially systemic corticosteroids and ACTH) (See additional prescribing points)
• Coadministration with sedatives, hypnotics, tranquillizers, narcotic analgesics, antihistamines and anticholinergics
• Coadministration with antidiabetics (See additional precrbing points)
• May impair ability to drive and operate machinery

Forms avail. in SA and covered in this monograph: tab

Long-term prevention of asthma
Prevention and treatment of allergic skin reactions
Prevention and treatment of allergic rhinitis

• Oral (srt): 2mg, in the evening

OR

• Oral (tab): 1mg, 12hrly, with morning and evening meals; Uptitrate to 2mg, 12hrly if needed

If susceptible to sedation

• Oral (tab): 1st week: 0.5mg, dly in the evening; Then: Increase to full therapeutic dose as stated above

Prevention of asthma: Ketotifen is not effective in aborting established attacks of asthma

2mg tablets should be swallowed whole

In the prevention of asthma, it may take several weeks of treatment to achieve the full therapeutic effect. If therapeutic response after 4 weeks of treatment is insufficient the doses may be increased gradually depending on body mass

In introducing ketotifen therapy, care should be taken to slowly taper off the dose of other anti-allergic agents that the patient may be receiving

Paed. forms avail. in SA and covered in this monograph: syr

Long-term prevention of asthma
Prevention and treatment of allergic skin reactions
Prevention and treatment of allergic rhinitis

2mg tablets should only be used in children with body mass ≥25kg

In the prevention of asthma, it may take several weeks of treatment to achieve the full therapeutic effect. If therapeutic response after 4 weeks of treatment is insufficient the doses may be increased gradually depending on body mass

In introducing ketotifen therapy, care should be taken to slowly taper off the dose of other anti-allergic agents that the patient may be receiving

Pregnancy

• Contraindicated
• Safety in pregnancy is not established

Breastfeeding

• Contraindicated 
• Safety in breastfeeding is not established

Fertility 

• No information available

Renal Impairment

• Caution; no information available 

Hepatic Impairment

• Contraindicated 

Elderly

• Caution; no information available

Porphyria Information

• Not yet classified (NC) 

Drugs in Sport

• Permitted - No warnings

Central Nervous System Disorders

• Sedation
• Dizziness
• Excitation
• Irritability
• Insomnia
• Nervousness
• Drowsiness

Gastrointestinal Disorders

• Dry mouth

Hepatobiliary Disorders

• Increased liver enzymes
• Hepatitis

Genitourinary Disorders

• Cystitis

Endocrine and Metabolic Disorders

• Increased appetite
• Mass gain

Skin and Subcutaneous Tissue Disorders

• Severe skin reactions
  - Erythema multiforme
  - Stevens-Johnson syndrome

No information available

• Platelet counts (when coadministered with oral antidiabetic agents)

Special precautions

• If intercurrent infection occurs, ketotifen treatment must be supplemented by specific anti-infectious therapy
• Anti-asthmatic agents already in use should never be withdrawn abruptly when long-term treatment with ketotifen is begun. This applies especially to systemic corticosteroids and ACTH because of the possible existence of adrenocortical insufficiency in steroid-dependent patients; in such cases, recovery of normal pituitary-adrenal response to stress may take up to one year
• A reversible fall in thrombocyte count in patients receiving ketotifen concomitantly with oral antidiabetic agents has been observed in a few cases. This combination should therefore be avoided

Ketotifen has anti-anaphylactic properties and anti-histaminic effects. Laboratory experiments have indicated the following properties of ketotifen, which may contribute to its activity; inhibition both of the acute bronchoconstrictor response to PAF (Platelet Activating Factor) and of PAF-induced airway hyper-responsiveness, inhibition of PAF-induced accumulation of eosinophils in the airways, inhibition of the release of such chemical mediators as histamine and leukotrienes and antagonism of acute bronchoconstriction due to leukotrienes. Ketotifen exerts H1-receptor blocking activity which can be clearly dissociated from the anti-anaphylactic properties.

  Tablet 1mg

• Zaditen (Novartis) originator

Tablet 2mg

• Zaditen (Novartis) originator

Syrup (per 5ml) 1mg 

• Adco-Ketotifen (Adcock Ingram)
• Adco-Zetofen (Adcock Ingram)
• Zaditen (Novartis) (Discontinued: 24/01/2020)

Also available in the following forms: Eye drop