Preventing Recurrence of Renal Colic

(Australia—Australian Family Physician, January 2001, p. 36.) Approximately 10 percent of men and 4 percent of women have renal calculi and 60 to 80 percent experience at least one recurrent episode. Peak incidence is between 20 and 50 years of age. The stone should always be analyzed if possible and the patient should be investigated for correctable predisposing factors. After the acute episode, all patients should be encouraged to drink at least two liters of water daily, more if the patient has increased fluid loss. Patients should drink at least one glass of water every hour to maintain urine that is clear or very pale yellow in color. Consumption of oxalic acid in foods such as rhubarb, asparagus, spinach, peanuts, chocolate, tea and coffee should be restricted, and intake of purines (found in organ meats, sardines, beans, beer and red wine) should also be reduced. Increasing dietary consumption of fiber, cereal, fruit and vegetables can increase citrate excretion, which inhibits stone formation. Conversely, refined carbohydrates, sugar and sodium increase calcium excretion and increase the risk of recurrent stone formation. Patients who recurrently form calcium oxalate or phosphate stones may benefit from the use of thiazide diuretics. Patients with uric acid stones, hyperuricosuria, hyperuricemia, and some patients with recurrent calcium oxalate stones, may benefit from prophylaxis with allopurinol. Urinary tract infections should be treated promptly and antibiotic prophylaxis may reduce the frequency of symptomatic urinary tract infections and the likelihood of stone formation.

Improving Asthma Control in Adults

(Australia—Australian Family Physician, February 2001, p. 114.) Australian guidelines on the management of asthma recommend the introduction of corticosteroids for any adult who uses more than four doses of inhaled beta-agonist medication per week. For mild to moderate asthma, a typical dosage of beclomethasone is 800 μg per day. Airway responsiveness may continue to improve over several months, but clinical improvement is achieved in about eight weeks. Acute exacerbations of symptoms usually require five to 10 days of high-dose therapy. If symptoms are well controlled on steroid therapy after three months, a reduction in the dosage may be cautiously attempted to “back titrate” to the lowest effective dose. One method is to reduce the dosage by one fourth every three months. If asthma is poorly controlled with inhaled corticosteroid medication, consideration should be given to compliance and technique in using inhalers before the dosage is increased. Potential triggering and exacerbating factors should also be sought and eliminated. If symptoms are poorly controlled using 1,600 μg of beclomethasone daily, the therapeutic benefits of increasing the dosage are marginal compared with the risk of side effects. The addition of a long-acting beta₂-agonist offers greater benefit than continuing to increase the dosage of inhaled corticosteroid. The leukotriene receptor antagonists are a new class of asthma medications. They are potent bronchoconstrictors that influence the inflammatory process. The optimal role of these drugs has not been determined, but they may be particularly useful in patients with exerciseinduced asthma or those who have difficulty with inhalers or who have side effects from inhaled corticosteroids.

Choices in Administration of Migraine Drugs

(Canada—Canadian Family Physician, February 2001, p. 322.) Migraine is a common condition that results in an estimated $17 billion of medical care and loss of productivity each year in the United States. Acute attacks require effective treatment of rapid onset, but the choice of agents may be limited because of vomiting or disturbed gastrointestinal function. Many medications are currently available to relieve the symptoms of acute migraine attacks. More than 70 percent of patients prefer oral treatments because of their convenience. To improve absorption, prokinetic and other agents may be added to oral migraine medication. In addition, manufacturers are rapidly developing wafers, oral disintegrating tablets and other novel forms of oral and sublingual migraine medications. While parenteral administration provides rapid onset of treatment, not all medications are available in this form. The principal limitations of parenteral treatment are discomfort, the need for training in administration and low patient acceptability. The rectal route of administration is unpopular with patients but provides an effective route when vomiting limits oral administration. Besides ergotamine and prochlorperazine, very few migraine-specific medications are available in suppository form. Nasal administration of migraine medication is rated as highly acceptable by patients and several agents are now available in this form. Onset of action is rapid and side effects include local irritation and unpleasant taste.