Heat and chronic medications in Puerto Rico: blood pressure, diuretics, diabetes and dehydration

In Puerto Rico heat and humidity are part of the whole year, not only summer. When you sweat a lot you lose water and salts, and your body has to work harder to keep blood pressure, blood sugar and temperature steady. If you also take chronic medications, heat can weigh more.

The CDC explains, in its guidance for clinicians, that some medicines can make it harder to stay hydrated, regulate temperature or sweat, and that heat can affect how medicines are stored and how they act. That does not mean you should stop taking them: it means it is worth reviewing your plan with your doctor before a stretch of strong heat.

This guide is informational. It does not replace your doctor and it does not tell you to change your dose. If you think your treatment needs an adjustment for the heat, the doctor can review it with you by video and decide what is appropriate for you.

Diuretics ("water pills") make the kidneys remove more fluid and salt. In the heat you are already losing fluid through sweat, so the two together can leave you dehydrated more easily. Other high blood pressure medicines, such as ACE inhibitors, angiotensin receptor blockers (ARBs) and beta blockers, also appear on the CDC's list of medicines to keep in mind in very hot weather.

Signs that you are getting dehydrated or that your blood pressure is dropping too low include intense thirst, dry mouth, little or dark urine, dizziness when standing, weakness and headache. See our guide to dehydration.

With type 2 diabetes, dehydration matters for several reasons. When blood sugar runs high, the body passes more fluid in the urine; if you also sweat a lot, the water loss adds up. Dehydration can also affect the kidneys, and the kidneys influence how the body handles some diabetes medicines, such as metformin. Some medicines, like SGLT2 inhibitors, also increase urination and carry warnings about dehydration and illness. That is why you should ask your doctor what to do if you get sick or can't drink fluids; it is not something to decide alone at home.

Check your blood sugar more often on very hot days if your doctor has already told you to, and write the results down. Heat and sweating can also change how a low blood sugar feels. Learn your symptoms and keep your plan for treating a low within reach.

According to the FDA, insulin in the manufacturer's vials or cartridges, opened or unopened, may be left unrefrigerated between 59 °F and 86 °F (15 °C to 30 °C) for up to 28 days and still work. Never leave it in a parked car, glove box, a suitcase in the sun or near a stove, because in Puerto Rico those spots easily go past 86 °F. Do not use insulin that has frozen. If you are unsure about insulin that got hot, ask your pharmacist or the manufacturer.

Many pill labels say to store them at room temperature, away from moisture and heat. Avoid the bathroom (shower steam), the kitchen near the stove, and the car. Keep them in the original closed container in a cool, dry cabinet. If a pill changed color or smell or stuck together, take it to the pharmacy and ask before taking it.

If you travel or go to the beach, carry your medicines with you in a shaded bag, not in the trunk. See also how to travel with your medications.

The CDC's list is long, and not everything applies to everyone. If you take any of these, ask your doctor or pharmacist what to keep in mind in the heat, without changing anything on your own:

According to the CDC, older adults, infants and young children, people with chronic conditions (heart, kidney, diabetes, high blood pressure), people who take certain medicines, and people who work or exercise outdoors are more exposed. If an older adult who takes several medicines lives with you, go over their list with them. See our guide to heat stroke and heat exhaustion.

Dr. Diana Nieves Castro, a general practice physician licensed in Puerto Rico with several years of emergency-department experience, sees you by video. In a follow-up visit she reviews your treatment, asks how you have been doing in the heat and, if appropriate, prescribes and we send your prescription to your pharmacy. It is a prescription refill of medicine you already take, and part of your chronic-condition care.

The doctor can review your blood pressure, your diabetes and your readings, talk with you about dehydration and, if a test would help, give you a lab order for a lab near you. Doctor online 24/7: request online 24/7 and you choose your time when you book. Every day, any time (Puerto Rico time).

You need to be physically in Puerto Rico during the visit, and visitors are welcome. For patients under 21, a parent or legal guardian stays on camera for the whole visit and shows photo ID.

Video doctor visits 24/7 — book online and choose your time right away.

A follow-up visit covers a refill of a medicine you already take. A new problem is a doctor visit. If the doctor finds during a follow-up visit that you need a full visit, she explains why and, with your consent, you pay the difference.

The price is the same for every age, with no membership. Your card is charged when you request the visit, and you get a full refund if the clinic can't see you. A doctor's note after your visit is included at no extra charge. The service is run by The Health Initiative, a nonprofit. See pricing or book your visit.

An outage on a hot day adds two risks: no fan or air conditioning, and the fridge stops cooling. For insulin, see the section above (up to 28 days between 59 °F and 86 °F). Stay in the coolest spot in the house, drink fluids, wear light clothing, and don't stay alone if you are an older adult. For refrigerated medicines other than insulin, ask your pharmacist whether they are still usable.

Your visit can be by video or by phone, depending on the service and what the doctor considers appropriate. If the signal is weak, connect from the spot with the best coverage and charge your phone ahead of time. See our guide to medications and hurricanes to prepare your kit, and 24-hour pharmacies.

Call 911 or go to the ER if there is confusion, slurred speech, fainting, seizures, very hot skin with a very high temperature, or extreme weakness in the heat: these can be signs of heat stroke. While help arrives, move the person to shade or a cool place, remove extra clothing and cool them with wet cloths on the head, neck, armpits and groin. Give nothing by mouth if they are confused or unconscious.

Also go to the ER for chest pain, trouble breathing, stroke signs, persistent vomiting that stops you from keeping fluids or your medicines down, or very high or very low blood sugar with confusion or extreme tiredness. Don't wait for a video visit. See when to go to the ER.