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What Is the Relationship Between Methamphetamine Use and IPAH?
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Key Point
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Patients with idiopathic pulmonary arterial hypertension are more likely than those with other forms of pulmonary hypertension to have used stimulants such as methamphetamine. |
SAN DIEGO—Fenfluramine is a diet drug with known connections to idiopathic pulmonary arterial hypertension (IPAH). New research suggests that its pharmacologic cousin, methamphetamine, may also contribute to the condition.1
Richard N. Channick, MD, and colleagues evaluated rates of stimulant use—cocaine, methamphetamine, and amphetamine—in 340 patients with IPAH, PAH with known risk factors, or chronic thromboembolic pulmonary hypertension (CTEPH). The majority of the participants were women: 56% of the CTEPH group, 72% of the IPAH group, and 89% of the group with PAH with known risk factors were female. According to Dr. Channick, Professor of Clinical Medicine at the University of California, San Diego, Medical Center, “This is an epidemiologic case-control study confirming what has been long suspected—that stimulant drugs are associated with the development of pulmonary arterial hypertension.”
DRUG USE AND IPH
A history of stimulant use was reported in 29% of IPAH patients, versus about 4% of patients with CTEPH and PAH with known risk factors. “The low percentage of stimulant-using patients in the ‘PAH with known risk factors’ and CTEPH groups probably more closely parallels the usage rates in the general population,” explained Dr. Channick. Adjusted odds ratios for stimulant use were 10.14 (95% CI, 3.39 to 30.3) for IPAH versus PAH with known risk factors, and 7.63 (95% CI, 2.99 to 19.5) for IPAH versus CTEPH.
The authors asserted that “the finding that 28 of 97 patients with IPAH have a history of stimulant use is important and suggestive of an association.” Dr. Channick added, “Given the increasing crisis of methamphetamine abuse in this country, its association with a potentially fatal lung disorder is important information for clinicians and the public.”
He acknowledged that even though most of the patients in his study did not use stimulants, asking patients in a nonjudgmental way about drug use is advisable. “In a patient with known or suspected pulmonary hypertension, specific questions regarding current or past methamphetamine or cocaine use should be asked.”
The researchers noted that amphetamines and fenfluramine have pharmacologic similarities that may underlie the association between stimulants and IPAH. There may be a receptor or pathway that these drugs share, that may thus influence IPAH. Although the mechanism behind stimulant use and IPAH is not known, Dr. Channick speculated that “release of norepinephrine leading to constriction and proliferation in susceptible pulmonary vessels, release of serotonin with subsequent vascular remodeling, and direct vascular toxic effects of inhaled stimulants” could be to blame.
Dr. Channick believes that future research must elucidate the mechanisms of IPAH in patients who have used stimulants and that it should examine whether legal stimulants, such as drugs for attention deficit disorder, can contribute to IPAH as well.
—Tamara Gibb
Reference
1. Chin KM, Channick RN, Rubin LJ. Is methamphetamine use associated with idiopathic pulmonary arterial hypertension? Chest. 2006;130:1657-1663.
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