Since you are taking the medications for 5 months now, the black spots may not be due to the drugs taken.
However the cause of the black spots usually are prolonged antibiotic use, poor oral hygiene, use of tobacco, bacterial growth on tongue due to less immunity.
Next Steps
you must consult a dentist at your earliest without further delay.
Health Tips
Don't try any home remedies and visit your dentist and get proper diagnostics tests done as this is not a good sign of having black spots since 1 month now.