Side Effects:
If any of the following side effects occur while taking sulfamethoxazole / trimethoprim, check with your doctor immediately:
Rare
Abdominal or stomach pain
black, tarry stools
blistering, peeling, or loosening of the skin
changes in skin color
chest pain
chills
cough or hoarseness
dark urine
diarrhea
dizziness
fever with or without chills
general feeling of tiredness or weakness
headache
itching
joint or muscle pain
light-colored stools
loss of appetite
lower back or side pain
nausea
pain, tenderness, or swelling of the foot or leg
painful or difficult urination
pale skin
rash
red skin lesions, often with a purple center
red, irritated eyes
shortness of breath
sore throat
sores, ulcers, or white spots in the mouth or on the lips
swollen or painful glands
tightness in the chest
unpleasant breath odor
unusual bleeding or bruising
vomiting of blood
wheezing
yellow eyes or skin
Incidence not known:
Abdominal or stomach tenderness
back, leg, or stomach pains
bleeding gums
blindness or vision changes
blisters, hives, or itching
bloating
blood in the urine or stools
bluish-colored lips, fingernails, or palms
burning, crawling, itching, numbness, painful, prickling, "pins and needles", or tingling feelings
burning of the face or mouth
chest pain
cloudy urine
confusion
constipation
continuing ringing or buzzing or other unexplained noise in the ears
convulsions
cracks in the skin
decreased frequency or amount of urine
diarrhea, watery and severe, which may also be bloody
difficulty with breathing
difficulty with swallowing
fainting spells
general body swelling
general feeling of discomfort or illness
hair loss
hearing loss
hives
increased thirst
indigestion
irregular heartbeat
large, flat, blue, or purplish patches in the skin
large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
loss of heat from the body
muscle or joint pain
nosebleeds
not able to pass urine
numbness or tingling in the hands, feet, or lips
pain or burning while urinating
pinpoint red spots on the skin
puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
raised red swellings on the skin, the buttocks, legs, or ankles
redness of the white part of the eyes
redness, swelling, or soreness of the tongue
sores, ulcers, or white spots on the lips or in the mouth
soreness of the muscles
stiff neck or back
swelling of the face, hands, legs, and feet
unsteadiness, trembling, or other problems with muscle control or coordination
unusual weight loss
weakness in the hands or feet
weakness or heaviness of the legs
weight gain
Minor Side Effects
Some sulfamethoxazole / trimethoprim side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:
More common:
Passing of gas
Incidence not known:
Discouragement
feeling of constant movement of self or surroundings
feeling sad or empty
increased sensitivity of the skin to sunlight
irritability
lack of feeling or emotion
loss of interest or pleasure
nervousness
redness or other discoloration of the skin
seeing, hearing, or feeling things that are not there
sensation of spinning
severe sunburn
trouble concentrating
trouble sleeping
uncaring
weight loss