Guanfacine

The FAA's Do Not Issue table lists centrally acting hypertensives, including but not limited to clonidine, guanabenz and methyldopa, and its psychiatric or psychotropic medications, even when used for conditions other than mental health, including attention deficit disorder (ADD) or ADHD medications; the FAA's table says the examiner should defer the exam, and it also says do not issue a medical certificate.

FAA rule for blood pressure medication: The FAA's hypertension worksheet (CACI) refers to the antihypertensive sheet for acceptable medications, and allows combinations of up to 3 of the classes it lists -- alpha blockers, beta-blockers, calcium channel blockers, diuretics, ACE inhibitors, ARBs, direct renin inhibitors and direct vasodilators -- and lists centrally acting antihypertensives, such as clonidine, as not acceptable. The Guide's hypertension table says the number of medications counts each component (for example, lisinopril/HCTZ is 2 medications), and that with 4 or more acceptable medications the examiner should defer. FAA, CACI – Hypertension Worksheet