Indications: Moxonidine, a centrally acting drug, is licensed for mild to moderate essential hypertension. It may have a role when thiazides, beta-blockers, ACE inhibitors and calcium-channel blockers are not appropriate or have failed to control blood pressure.

Cautions: renal impairment (Appendix 3); avoid abrupt withdrawal (if concomitant treatment with beta-blocker has to be stopped, discontinue beta-blocker first, then moxonidine after few days); interactions: see Appendix 1 (moxonidine)

Contra-indications: history of angioedema; conduction disorders (sick sinus syndrome, sino-atrial block, second- or third-degree AV block); bradycardia; life-threatening arrhythmia; severe heart failure; severe coronary artery disease, unstable angina; severe liver disease or severe renal impairment; also on theoretical grounds: Raynaud’s syndrome, intermittent claudication, epilepsy, depression, Parkinson’s disease, glaucoma; pregnancy (Appendix 4); breast-feeding (Appendix 5)

Side-effects: dry mouth; headache, fatigue, dizziness, nausea, sleep disturbance (rarely sedation), asthenia, vasodilatation; rarely skin reactions

Dose: 200 micrograms once daily in the morning, increased if necessary after 3 weeks to 400 micrograms daily in 1–2 divided doses; max. 600 micrograms daily in 2 divided doses (max. single dose 400 micrograms)