Prophylaxis Against Migraine

The objective of prophylactic treatment of migraine is to reduce the frequency and severity of attack, and making acute attacks more responsive to abortive therapy while improving patient's quality of life.

Indications of prophylactic therapy include :

• When patients use abortive medication for more than three a week.
• Contraindication to or ineffectiveness of medications used to control an acute attack.
• Special types of migraine headaches such as hemiplegics migraine which may produce profound disruption or risk of permanent neurological injury.

The classes of drugs used for the prophylaxis and factors influencing their choice are summarized below :

• Beta-blocking adrenergic drugs are particularly effective in patients with migraine associated with stress and hypertension. They are supposed to exert their effect due to their 5-HT2B antagonism property and blockade of the nitric oxide activity. However the adverse events associated with beta blockers must be considered before they are prescribed. All beta-blockers can cause fatigue, depression, memory disturbances, male impotence and orthostatic hypotension. They should not be given to patients with asthma and congestive heart failures. Commonly used beta blockers are propranolol, timolol and metoprolol.
• Serotonin receptor antagonists which are currently used for prophylaxis of migraine are : methylsergide, pizotifen, oxetorone and cyproheptadine.
• Methylsergide is one of the most effective antimigraine prophylactic agent but long term use may cause pleural, pericardial or retroperitoneal fibrosis. However these problems can be avoided by close medical monitoring and by advising the patient to take one month "drug holiday" every 6 months.Cyproheptadine is effective prophylactic drug in children. It causes increase in appetite and drowsiness.Pizotifen is also associated with side effects like weight gain and sedation.
• Tricyclic antidepressants like amitryptytine and nortryptiline are effective when the attack is aggravated by tension, depression or insomnia. However, these drugs produces anticholinergic adverse event such as dizziness, dryness of mouth, blurred vision, urinary retention and increased appetite and weight gain.
• Gamma aminobutyric acid transaminase inhabitor and activator of glutamic acid decarboxylase such as sodium valproate, and Dival proex sodium are effective in reducing the severity and duration of migraine attacks. Adverse events include nausea, tremor transient hair loss, increase in appetite and weight gain. Hepatotoxicity and teratogenicity limit their use.
• Calcium channel blockers used in prophylaxis of migraine are verapamil and flunerazine. Flunerazine has more clinical efficacy compared to verapamil.
• High dose riboflavin, a co-enzyme in the electron transport chain was found to be effective in prophylaxis of migraine in several studies. Some minor adverse reaction associated with the use of riboflavin include diarrhoea and polyuria.
• Herbal drugs like Tanacetum parthenium (fever few) contaning sesquiterpene parthenolide as its main ingredient has been found to be effective in migraine prophylaxis. However abrupt discontinuation may increase migraine frequency. Some individual may also experience nervousness, insomnia, joint stiffness and pain after discontinuation of the drug.

Ginger (Zingiber officinate) and its active ingredients gingerols and shogaols are also reported to be effective in migraine prevention by inhibiting prostaglandin synthetase and leukotriene biosynthesis.

In addition, nonpharmacological measures such as educating the patient on various aspects of migraine are also employed as part of the treatment.

Nonpharmacologic measures of preventing migraine :

• Maintain regular sleeping, eating and exercise habits.
• Avoid triggers such as tobacco, chocolates, caffeinated beverages, red wine, food containing sodium glutamate and nitrites.
• Avoid excessive stress producing activities and practice relaxation techniques.