Crataegus monogyna, more commonly known as hawthorn, has long played a role in herbal medicine as a treatment for symptoms of heart disease. The University of Maryland Medical Center (UMMC) notes that hawthorn can help treat mild to moderate congestive heart failure, as well as angina, a disorder involving low blood flow to the heart. Hawthorn leaves, flowers and berries are used in both dry and liquid extracts. Side effects are uncommon, but there are some important contraindications.
Although hawthorn berry can be effective at treating heart disease symptoms, the UMMC cautions people not to self-medicate with hawthorn without a doctor's input. Heart disease is a serious condition and requires medical supervision. If you are taking hawthorn and experience more heart disease symptoms than usual while walking or exercising, seek emergency medical attention. Symptoms to watch for include more angina attacks, more pain or more exhaustion than usual. Hawthorn overdose also affects the cardiovascular system, according to the Memorial Sloan-Kettering Cancer Center. Taking too much hawthorn could result in low blood pressure, or hypotension, with symptoms of lightheadedness or fainting. Irregular heartbeat also can occur with a hawthorn overdose.
Pregnant Women and Children
Pregnant women should not use hawthorn berry, because research is lacking on whether this herb is safe during pregnancy, according to the People's Pharmacy. Hawthorn extract can decrease uterine tone, which may make it unsafe during pregnancy. Research also is lacking on the safety of hawthorn during breastfeeding. Additionally, the UMMC also advises against giving hawthorn to children.
As with any herbal remedy, some people may be allergic to hawthorn berry. If you are allergic to any plants in the Rosaceae, or rose, family, you may be more likely to experience a negative reaction to hawthorn. Some of these plants include roses, dropwort, meadowsweet, strawberries, pears, apricots, apples and sour cherries.
Hawthorn is contraindicated with many types of medication, according to the UMMC. Talk with your health care provider before using hawthorn berry if you are taking drugs for any health condition. Hawthorn may increase the effects of digoxin, used for heart arrhythmia; beta blockers and calcium channel blockers, used to dilate blood vessels and reduce blood pressure; and central nervous system depressants. Hawthorn has blood-thinning properties, so if you are taking anticoagulant or antiplatelet medications, ask your physician to reassess bleeding time once you start using this herb.