(1995; 152 pages) [French] [Spanish]
Group: antimicrobial agent
Capsule or tablet 100 mg (as hyclate)
Doxycycline is derived from and closely related to oxytetracycline, and has an identical spectrum of activity. It differs from the tetracyclines in that it is more extensively absorbed and more lipid-soluble, and it possesses a longer serum half-life that is independent of the patient’s renal status.
Short-term prophylaxis of multiple-drug-resistant falciparum malaria. Because of limited experience, doxycycline should be used for prophylaxis only by persons who cannot tolerate mefloquine or who visit areas where mefloquine is no longer effective.
Dosage and administration
Adults: 100 mg daily for up to 8 weeks.
Children over 8 years: 1.5 mg/kg daily for up to 8 weeks.
Prophylaxis should be started 1 day before exposure and continued for 4 weeks after the last risk of exposure.
• Known hypersensitivity.
• Age under 8 years, since skeletal deposition can result in retardation of bone growth, hypoplasia of dental enamel and permanent brown discoloration of teeth.
Oesophageal ulceration may be averted if the patient sits or stands up for a few minutes while the tablets are swallowed, and if they are always washed down immediately with a glass of water.
Other symptoms of gastrointestinal irritability can be reduced if doxycycline is taken with a meal, but milk products must be avoided since they reduce absorption.
Use in pregnancy
Doxycycline is generally contra-indicated in pregnancy. It impairs skeletal calcification in the fetus and can result in abnormal osteogenesis and hypoplasia of dental enamel.
Gastrointestinal irritation is common and phototoxic reactions and increased vulnerability to sunburn have been reported.
Transient depression of bone growth is largely reversible, but discoloration of teeth and enamel hypoplasia are permanent.
The action of oral anticoagulants may be potentiated. Severe renal failure has been reported in patients who have received a halogenated anaesthetic agent while taking doxycycline.
Capsules and tablets should be kept in well-closed containers, protected from light.