Fever with decreased appetite is not usual for a patient on Anti TB medications.
Points to be considered
Was his TB confirmed microbiologically ( Was it Pulmonary or extra pulmonary)
Is patient getting adequate regime
Compliance to the treatment (DOTS ?)
Any co morbid condition
These points are to be evaluated by a Pulmonologist, so better to Consult one
Next Steps
Consult a Pulmonologist as soon as possible
Health Tips
Continue Anti TB medications