Appropriate cephalexin dose depends on the type of infection a patient is being treated for, the patient’s age, and any underlying medical issues the patient may suffer from. This antibiotic is taken orally in tablet or liquid form, which may be flavored for younger patients who find the taste unpleasant. It is typically taken several times a day to keep concentrations in the body high and it is important to take the doses at the same time every day.
One concern is the type of infection. Standard doses range from 250 to 1,000 milligrams daily, taken over the course of several divided doses for one to two weeks. A medical professional may base the dose on experience with that kind of infection and the patient’s medical history. A one-time cephalexin dose of 2 grams may be recommended as prophylaxis before surgery to prevent endocarditis, an infection of the valves of the heart which can cause serious medical complications.
Age is another factor, because younger patients may weigh much less than adults. For pediatric dosing, the cephalexin dose may be calculated by weight to make sure the patient doesn’t get too much of the antibiotic. Weight considerations can also play a role in significantly overweight or underweight adults for whom the standard dose may not be appropriate. Using an undersized cephalexin dose might promote the development of antibiotic resistance by killing off some organisms and allowing those with resistant genes to thrive, which is not desired.
The patient’s medical history can also be a concern with cephalexin dose decisions. People with kidney problems may not be able to metabolize the medication as well, and could end up with blood serum levels that are too high. They may require a dosage adjustment to protect the kidneys and make sure the dosage is adequate after the medication is metabolized. This can be a particular concern for people using dialysis to support failing kidneys that have trouble processing medications on their own.
Potential medication conflicts may be another concern. If there are worries about a cephalexin interaction, the patient may need to temporarily adjust a medication schedule or take extra precautions. Antibiotics can potentially decrease the effectiveness of hormonal birth control, for example, making it important to use a backup method to prevent pregnancy. Patients should discuss all the medications they take, including over the counter drugs, to determine if there is a risk of interaction that may need to be addressed.