Pregnancy and breast feeding
Its use during pregnancy is contraindicated, although it has been placed in Australian pregnancy category C. Its use during the first trimester (during organogenesis) and 12 weeks prior to pregnancy has been associated with an increased risk of congenital malformations, especially malformations associated with maternal folic acid deficiency (which is most likely related to the mechanism of action of co-trimoxazole) such as neural tube defects such as spina bifida, cardiovascular malformations (e.g. Ebsteins anomaly), urinary tract defects, oral clefts, and club foot in epidemiological studies. Its use later on during pregnancy also increases the risk of preterm labour (odds ratio: 1.51) and low birth weight (odds ratio: 1.67). Animal studies have yielded similarly discouraging results.It appears to be safe for use during breastfeeding as long as the baby is healthy. Babies
Its use in those less than 2 months of age is not recommended due to the risk of adverse side effects. Adverse effects
Common side effects include nausea, vomiting, rash, and diarrhea. Severe allergic reactions and Clostridium difficile infection may occasionally occur. Its use in pregnancy is not recommended. It appears to be safe for use during breastfeeding as long as the baby is healthy. Trimethoprim/sulfamethoxazole generally results in bacterial death. It works by blocking the making and use of folate by the microorganisms. Contraindications
Contraindications include the following:

Interactions
Its use is advised against in people being concomitantly treated with:

Overdose
Likely signs of toxicity include:

The recommended treatment for overdose includes:
Administration of activated charcoal
Stomach pumping
General supportive measures
Haemodialysis, which is moderately effective in clearing co-trimoxazole from the plasma.
There is a risk of premature death in affected individuals due to deep vein thrombosis and pulmonary embolism caused by the vessel malformations that are associated with this disorder. Because of carrying excess weight and enlarged limbs, arthritis and muscle pain may also be symptoms. Further risks may occur due to the mass of extra tissue.The disorder itself does not uniformly cause learning impairments: the distribution of intelligence deficits among those with Proteus syndrome appears higher than that of the general population, although this is difficult to determine with statistical significance. In addition, the presence of visible deformity may have a negative effect on the social experiences of the affected individual, causing cognitive and social deficits.Affected individuals are at increased risk for developing certain tumors including unilateral ovarian cystadenomas, testicular tumors, meningiomas, and monomorphic adenomas of the parotid gland.Hemimegalencephaly is often found to be associated. Orthopaedic features
The musculoskeletal manifestations of Proteus syndrome are frequent and recognizable. Patients tend to demonstrate a unique pattern of skeletal abnormalities. The orthopaedic features are usually bilateral, asymmetrical, progressive and involving all four limbs and spine. Affected patients usually have localized periarticular limb distortions, limb length discrepancy, and spine deformity. Patients with Proteus syndrome can have regular bone configuration and contours despite the bone enlargement. Patients can also exhibit deformation of the skull in the form of dolichocephaly or elongated skull and facial abnormalities. Because of the rarity of the syndrome and the variability of signs, the orthopaedic management should be individualized. Genetics
In 2011 researchers determined the cause of Proteus syndrome.