Crataegus laevigata, C. monogyna, English hawthorn, haw, may, maybush, mayflower
The use of hawthorn dates back to the ancient Greeks, but the plant became popular in European and American herbal medicine toward the end of the 19th century. The active compounds of hawthorn are obtained from the berries, flowers, and leaves of the Crataegus species, most commonly from C. laevigata or C. monogyna. The primary ingredients responsible for the pharmacologic effects of hawthorn include flavonoids and procyanidins.
Hawthorn flavonoids increase myocardial contraction by dilating coronary blood vessels, reducing peripheral resistance, and reducing oxygen consumption. They also lower blood pressure by inhibiting angiotensin-converting enzyme. The procyanidins slow the heart rate, lengthening the refractory period, and also have mild central nervous system (CNS) depressant effects. Hawthorn’s pharmacologic effects usually develop slowly. Hawthorn is available as dried leaves, liquid extract, and tincture, in products such as Hawthorne Formula and Hawthorne Power.
Hawthorn is used to regulate blood pressure and heart rate and to treat atherosclerosis. It’s used as a cardiotonic and as sedative for sleep. Hawthorn is also used in mild cardiac insufficiency, heart conditions not requiring digoxin, mild stable forms of angina pectoris, and mild forms of bradycardia and palpitations.
- Dried fruit: 300 mg to 1,000 mg three times a day by mouth
- Liquid extract (1: 1 in 25% alcohol): 0.5 to 1 ml three times a day by mouth
- Oral use: 5 g, or 160 to 900 mg of extract
- Tincture (1:5 in 45% alcohol): 1 to 2 ml three times a day by mouth.
Side effects of hawthorn may include agitation, dizziness, fatigue, headache, circulatory disturbances, palpitations, GI complaints, nausea, rash on hands, and sweating. The herb’s action is similar to that of a class III antiarrhythmic. Use with antiarrhythmics could enhance this action. Increased risk of hypotension when given with antihypertensives or nitrates. Increased risk of cardiac toxicity when used with cardiac glycosides. Additive depressant effects with CNS depressants.
Patients with hypersensitivity to hawthorn or severe renal or hepatic impairment, children, pregnant patients, and breast-feeding patients should all avoid hawthorn use.
- High doses may cause hypotension and sedation. Monitor patient for CNS adverse effects, and monitor blood pressure.
- Hawthorn may interfere with digoxin’s effects or serum monitoring.
- Hawthorn shouldn’t be used for benign arrhythmias.
- If patient has heart failure, he should only use hawthorn under close medical supervision and in combination with other standard treatments, only as prescribed.
- Observe patient closely for adverse reactions, especially adverse CNS reactions.
- Warn patient not to treat cardiac symptoms such as edema or angina before seeking appropriate medical evaluation because doing so may delay diagnosis of a potentially serious medical condition.
- Advise patient to use hawthorn only under medical supervision.
- Advise patient to use caution when performing activities that require mental alertness because of potential CNS adverse effects.
- Warn patient that hawthorn won’t stop an angina attack.
- Instruct patient to notify his health care provider if he experiences dizziness, excessive sedation, irregular heartbeats, or any other adverse reactions.
- Instruct patient to seek emergency medical help if he experiences shortness of breath or chest pain.
- Tell patient to remind pharmacist of any herbal or dietary supplement that he’s taking when obtaining a new prescription.
- Advise patient to consult his health care provider before using an herbal preparation because a treatment with proven efficacy may be available.
Hawthorn has been studied extensively for its benefits in cardiovascular disease. It has also been studied for its vasodilatory action, vasorelaxant effects, and effects in myocardial ischemia. It’s been investigated for the prevention and treatment of atherosclerosis, and for hypertension. The ability to effectively treat elective mutism has also been observed. These studies indicate that hawthorn may have beneficial effects in cardiovascular disease such as ischemia, angina, and atherosclerosis. The plant also possesses lipid lowering and antihypertensive actions.