SN instructed patient / caregiver educated on medication Ethambutol. SN explained to patient that Ethambutol is an anti - tuberculous medication indicated for mycobacterial diseases such as Mycobacterium Avium Complex ( MAC ) and is usually used in combination with other anti - mycobacterial anti - infectives. SN explained that the side effects of this medication includes optic neuritis, hepatitis, abdominal pain, headaches, joint pain, fever, nausea and vomiting. SN instructed patient / caregiver to notify physician ( MD ) if experiencing persistence or worsening of side effects.