Effect of Zaditen on serum neutrophil chemotactic activity in exercise-induced asthma

Mast cell stabilizer ketotifen fumarate reverses inflammatory but not neuropathic-induced mechanical pain in mice

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Our preclinical findings indicate that ketotifen fumarate's analgesic effects are MC-dependent, and the case series report presented supports its use for the treatment of chronic pain.

Introduction:

Mast cell (MC) activation could establish a positive feedback loop that perpetuates inflammation and maintains pain. Stabilizing MCs with ketotifen fumarate (KF) may disrupt this loop and relieve pain.

Objective:

We aimed to test the effect of treatment with KF in pain assays in mice and in a case series of patients with chronic widespread pain.

Methods:

The analgesic effect of KF was tested in CD-1 mice injected with formalin, complete Freund's adjuvant, or subjected to spared nerve injury. In addition, wild-type (C57BL/6) and MC-deficient (C57BL/6-Kit^W-sh/W-sh) mice were injected with formalin or complete Freund's adjuvant and treated with KF. Patients with chronic widespread pain (n = 5; age: 13–16 years) who failed to respond to standard of care participated in a 16-week treatment trial with KF (6 mg/d). Ketotifen fumarate's therapeutic effect was evaluated using the patient global impression of change.

Results:

In the mouse experiments, KF produced dose- and MC-dependent analgesic effects against mechanical allodynia in the acute and chronic inflammatory pain but not neuropathic pain assays. In the patient case series, 4 patients reported that activity limitations, symptoms, emotions, and overall quality of life related to their pain condition were “better” or “a great deal better” since beginning treatment with KF. This was accompanied by improvements in pain comorbid symptoms.

Conclusion:

Treatment with KF is capable of reducing established inflammatory-induced mechanical nociception in an MC-dependent manner in mice, and it may be beneficial for the treatment of chronic pain conditions.

Ketotifen. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in asthma and allergic disorders

Ketotifen is an orally active prophylactic agent for the management of bronchial asthma and allergic disorders. Accumulated evidence indicates that after 6 to 12 weeks of administration, ketotifen significantly reduces respiratory symptoms and the need for concomitant antiasthmatic drugs in about 70% and 50%, respectively, of patients with mild to moderate bronchial asthma. However, absolute improvement in lung function is generally slight. Ketotifen also has pronounced antihistaminic and antianaphylactic properties which result in moderate to marked symptom improvement in the majority of patients with atopic dermatitis, seasonal or perennial rhinitis, allergic conjunctivitis, chronic or acute urticaria or food allergy. Comparative trials with established agents--notably sodium cromoglycate (cromolyn sodium) in asthma and histamine H1-antagonists in allergic disorders--indicate that ketotifen has comparable clinical utility. Unlike inhaled sodium cromoglycate, ketotifen ameliorates the symptoms of asthma, rhinitis and dermatitis when present together in atopic patients. Patient acceptance of ketotifen is good, although sedation can be troublesome in older children and adults for the initial 2 weeks of treatment. Weight gain is another notable effect in a small percentage of patients. Thus, ketotifen appears to be a useful agent for the management of allergic disorders and bronchial asthma, particularly in patients for whom oral therapy is preferred. Although a lengthy run-in period is needed in the treatment of asthma, in those patients who respond, continued reduction in the frequency and severity of symptoms and in the use of additional antiasthmatic drugs can be anticipated.

Immunologic and therapeutic aspects of ketotifen

Ketotifen, a benzocycloheptathiophene, possesses asthma-prophylactic and antiallergic activities in a number of in vitro and in vivo systems: prevention of cutaneous and lung anaphylaxis in the rat and guinea pig; inhibition of dermal and bronchial antigen challenges in man; inhibition of mediator release from rat mast cells, human basophils, human neutrophils, and human and guinea pig chopped lung; reduction of human neutrophil activation induced by PAF-acether; functional antagonism of mediator effects in the guinea pig; blockade of H1-receptors and prevention and reversal of beta-adrenergic tachyphylaxis in the rat. These properties make ketotifen suitable for the long-term prophylaxis of bronchial asthma and for the prevention and treatment of other allergic disorders, such as allergic rhinitis and conjunctivitis, food allergy, and urticaria. Oral ketotifen (1 mg twice daily) is particularly convenient in the management of the multiple allergies often encountered in patients with atopy.