cefalexin monohydrate at a glance
Medicine class
First-generation cephalosporin antibiotic
Available forms
Tablets, capsules and oral liquid
Food
May be taken with or without food
Common effects
Nausea, diarrhoea and abdominal discomfort
What is cefalexin monohydrate used for?
Selected products are licensed for infections caused by susceptible organisms.
Respiratory tract infections
Middle-ear infection
Skin and soft-tissue infections
Bone and joint infections
Genito-urinary infections, including acute prostatitis
Dental infections
How does cefalexin monohydrate work?
It interrupts bacterial cell-wall synthesis, killing susceptible bacteria. Resistant organisms will not respond.
cefalexin monohydrate preparations and strengths
Capsule
Route: Oral
Strengths: 250 mg, 500 mg
Oral suspension
Route: Oral
Strengths: 125 mg/5 mL, 250 mg/5 mL
How to take cefalexin monohydrate
Take cefalexin exactly as directed. Swallow tablets or capsules with water. Measure liquid with the supplied oral syringe or medicine spoon, not a kitchen teaspoon.
It can be taken with or without food.
Shake oral suspension well before measuring it.
Follow the product label for storage and disposal because reconstituted liquids differ.
The selected tablet’s score helps with swallowing; it does not divide the tablet into equal portions.
cefalexin monohydrate side effects
Common or expected effects
- Diarrhoea
- Nausea
- Stomach pain or indigestion
- Vomiting
- Headache or dizziness
- Rash or itching
- Thrush
Get urgent medical advice
- Anaphylaxis, including facial or throat swelling and breathing difficulty
- Severe, persistent or bloody diarrhoea
- Blistering, peeling or widespread pustular skin reactions
- Yellow skin or eyes, dark urine or pale stools
- Unexplained bruising or other signs of a blood disorder
- Confusion, muscle jerks or seizures, particularly with renal impairment
cefalexin monohydrate in pregnancy
Cefalexin can be used at any stage of pregnancy, and most studies of cephalosporins have not shown harm to the baby. The prescriber should confirm that treatment is appropriate because untreated infection can also affect pregnancy.
cefalexin monohydrate while breastfeeding
Cefalexin is generally compatible with breastfeeding; only small amounts enter milk. Seek advice if the infant feeds poorly or develops diarrhoea, vomiting, oral thrush or a rash. Extra assessment may be appropriate for a premature or unwell infant.
cefalexin monohydrate interactions
Tell the prescriber or pharmacist about all medicines and supplements. Relevant interactions include:
Probenecid
May increase or prolong cefalexin exposure by reducing its renal excretion.
Metformin
Cefalexin can increase metformin exposure. The clinical importance is uncertain, but review may be appropriate.
Aminoglycosides, other cephalosporins or potent diuretics
Concurrent use may increase kidney toxicity risk, particularly in susceptible patients.
Zinc-containing supplements
Common questions about cefalexin monohydrate
Answers are fully visible for fast scanning and source review.
Does cefalexin monohydrate treat viral infections?
No. It acts against susceptible bacteria, not viral illnesses such as colds or flu.
Can it be taken with food?
Yes. It may be taken with or without food; taking it after food may help with nausea.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.