Hypertension Induced by St. John’s Wort

Abstract

St. John's wort extracts are among the most popular herb remedies that have especially been advocated for their favourable side-effect profile. Preliminary data suggest manifold mechanisms of action, such as norepinephrine, serotonine, and dopamine reuptake inhibition, similar to some synthetic antidepressants [1,3]. Hypertension may be an adverse effect of the serotonine, noradrenaline, and dopamine reuptake inhibitor venlafaxine [4]. We report a case of St. John's wort inducing hypertension. The assessment of this case was part of the Arzneimittelsicherheit in der Psychiatrie drug safety program [2].Mr. A, a 56-year-old man without previous psychiatric history and without significant physical particularities, decided to self-medicate with a St. John's wort extract (Ze 117 250 mg b. i. d.) in the context of a stressful personal situation. He had not taken any type of drug since months before and took no other drugs during the hypericum administration. He had never experienced cardiovascular problems, and his blood pressure had always been normal, ranging from 110±120/70±80. After 5 weeks of using this drug, a blood pressure of 160/110 was noticed during a pre-physical training examination. He discussed these findings with his brother, who is a physican. The pressure was monitored for 1 week, at different times of the day, with different devices at home as well as his brother's office. Blood pressure remained between 145±160/95±110 at all measurements. No other side effects were reported or observed. St. John's wort was then discontinued, and his blood pressure normalised after two days, returning and remaining at the usual range of 110±120/70±80. While so far a large of patients have been treated with hypericum extract without any reported effects on blood pressure, the clear temporal association and the lack of alternative explications suggest a causal correlation in our patient. Noradrenaline reuptake inhibition could be the underlying mechanism, as in other noradrenergic antidepressants. Effort should be made to identify and evaluate the relative therapeutic and toxic importance of various extract components. Although in the case of our patient the hypertension was moderate and did not put him at high immediate risk, patients with cardiovascular comorbidities may be at higher risk. This raises question about risks associated with the easy accessibility of such herbal remedies. References1 Di Matteo V, Di Giovanni G, Di Mascio M, Esposito E. Effect of acute administration of hypericum perforatum-CO 2 extract on dopamine and serotonin release in the rat central nervous system. Pharmacopsychiat 2000; 33: 14 ± 18 2 Grohmann R, Rüther E, Engel RR, Hippius H. Assessment of adverse drug reactions in psychiatric in patients with the AMSP drug safety program: methods and first results for tricyclic antidepressants and SSRI. Pharmacopsychiat 1999; 32: 21 ± 28 3 Müller WE, Singer A, Wonnemann M, Hafner U, Rolli M, Schäfer C. Hyperforin represents the neurotransmitter reuptake inhibiting constituent of hypericum extract....

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