DEAR DR. ROACH: I read an article about a study the Mayo Clinic did using 20 mg tablets of sildenafil for pulmonary arterial hypertension and that it improved walking distance by 75%. Is there an upper age limit for a person using this medication for pulmonary hypertension?
ANSWER: Pulmonary hypertension is different from regular or systemic high blood pressure. It’s not the kind that is measured with a blood pressure cuff.
In pulmonary hypertension, the elevated pressures are inside the lungs. There are five general classes of pulmonary hypertension, and people must undergo extensive diagnostic testing to determine which subclass they have. The goal is to find a cause that has a specific treatment. For example, subclass 2 is pulmonary hypertension due to heart disease of the left side of the heart, such as heart failure or valvular heart disease. Treating those can make the pulmonary hypertension better.
However, many people do not have a treatable underlying cause that can be identified, so doctors rely on general treatments to improve symptoms. One such is sildenafil, which is called Revatio when used for pulmonary hypertension, but it is the same drug as Viagra. It prolongs the effect of nitric oxide, a chemical in the blood that relaxes blood vessels in the lungs and reduces pressure. Sildenafil, like other drugs in the same class, significantly improved the distance a person could walk in six minutes. The 75% increase you noted is higher than most studies showed, however.
The study included subjects up to 81 years old. I do not think age alone would be a reason not to use these kinds of medications. These medicines should not be used in people taking nitrates (such as nitroglycerine) or those with very low systemic blood pressure.
DEAR DR. ROACH: I’ve been taking an ACE inhibitor and a calcium channel blocker for the past four months for high blood pressure as advised by my cardiologist. In my blood test a month ago, my vitamin D level was at 16. I’m also taking weekly vitamin B12 as advised by my neurologist. Can I take vitamin D2 (50,000 IU) as a weekly dose for six weeks to overcome vitamin D deficiency, or would it interfere with blood calcium balance?
ANSWER: Vitamin D will not interfere with the action of your ACE inhibitor or calcium channel blocker. Vitamin D usually has a very small (if any) effect on blood calcium levels, as these are tightly regulated through multiple means, especially the parathyroid hormone level and the kidneys.
I see many people who are given a six-week course of high-dose vitamin D2, such as the 50,000 units weekly for six weeks you were prescribed. I do not prescribe it that way, since many people wrongly feel that this will “cure” their low vitamin D, and they stop monitoring it after the course of treatment. Many people have inadequate vitamin D levels, and although there is some disagreement about what levels need to be treated, yours is in the range where everyone agrees treatment is necessary. For those who need it, ongoing supplementation of vitamin D is necessary, whether through pills, diet or sun exposure. For most people with a level as low as yours, oral supplementation is by far the most effective and safest treatment. I prefer 1,000-2,000 IU of vitamin D3 daily as a starting point for supplementation in most.
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Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to [email protected] or send mail to 628 Virginia Dr., Orlando, FL 32803.