As soon as fall turns to winter, you always seem to get sick. It starts with a cough, that transforms into a cold—or worse, the flu. It’s not just your imagination. When the heat kicks on, it creates dryer conditions where germs flourish, and the low temperatures suppress your immune response. It’s part of the reason why cough, cold, and allergy medications are so popular in December, and antibiotics are trending by January, according to SingleCare data on the prescription fills.
But why are medications used to treat and prevent skin disorders the most prescribed drugs in summer months? And what’s behind the spike in high blood pressure prescriptions in late spring?
Certain drug classes are more popular during different months of the year. A primary care physician and pharmacist help explain what’s behind these seasonal trends.
*According to SingleCare data on prescription fills.
Trending in January
Macrolides are a class of broad-spectrum antibiotics that treat a variety of bacterial infections—from ear infections and sore throat to respiratory illnesses like bronchitis and pneumonia. “During the cold winter months, cold and flu is more prevalent along with bacterial infections,” says Peace Uche, Pharm.D. “These germs are easily spread due to increased indoor activities as the close contact and decreased airflow may contribute to the spread of infections.”
It’s no surprise then, that there are so many fills of common macrolides, including Zithromax Z-Pak (azithromycin), clarithromycin (regular and extended release), and erythromycin in the depths of the winter months. “Macrolides are most commonly prescribed for pneumonia and upper respiratory infections at the height of the cough and flu epidemic. January occurs at the end of the holiday season when people come home, return back to their normal routines as well as when the doctors’ offices reopen,” says Nadia M. Shaukat, MD, of Paradocs Worldwide Inc.
In other words, along with happy memories, people bring home germs from sick loved ones or the ill passenger beside them on the plane, bus, or train. For those living in colder climates, the virus that causes the common cold multiplies in lower temperature—making you more susceptible to ear infections or respiratory problems as a result.
Trending in February
Antiviral medications do exactly what you’d expect: they help your body stave off viral infections. There are currently drugs that target 13 groups of viruses—the most common ones you’ve heard of treat influenza, HIV, herpes, and hepatitis. The most prescribed drugs in February? Five antivirals that treat the flu and herpes (to the tune of nearly half a million prescription fills).
Flu season peaks between December and February. That might explain why the antivirals that can reduce the severity and length of your symptoms are the most common drug class prescribed in February. “Tamiflu treats the flu during the height of the cold and flu season,” explains Dr. Shaukat. Both Tamiflu and its generic, oseltamivir phosphate, make the top five drugs this month.
It’s also a common time of year for illness, which can trigger herpes recurrences—more commonly known as cold sores. Stress, fatigue, viral infections, or changes in the immune system all make you more susceptible to an outbreak. “The change in seasons may pose a challenge to the immune system because exercise and intake of immune-boosters (i.e., vitamin-rich foods) may decrease during the winter months,” explains Dr. Uche. “These factors may lead to increased antiviral and antibiotic prescriptions.”
“The winter months are known as ‘cuffing’ season where there is an increase toward staying at home cuddling and sex,” says Dr. Shaukat. “It also overlaps with Valentine’s Day, where there is a cultural push toward having a date for that day.” All that extra romantic contact could increase transmission of herpes—both oral and genital. The combination of these factors could explain why three medications that slow the growth of the herpes virus fall in the most popular list: acyclovir, valacyclovir, and famciclovir.
Cough, cold, and allergy medications
Trending in March and December
Cough, cold, and allergy medications are a broad group that incorporates everything from cough suppressants and decongestants to antihistamines. It makes sense that prescriptions for these medications spike in December, when rhinovirus is spreading through offices, schools, and households like wildfire. “People tend to get colds as they stay in closer quarters with each other as the weather gets colder in December,” says Dr. Shaukat.
All of the top medications stop that pesky cough, or get that mucus out. Benzonatate, bromphen/pseudoephedrine HCl/dextromethorphan HBr, promethazine/dextromethorphan, promethazine/codeine, and virtussin A/C are all cough suppressants and expectorants.
But why does their popularity soar in March? “Allergy season may start to begin as the spring starts” in many regions of the United States, explains Dr. Shaukat. Trees, grasses, and pollens pop out, and start causing respiratory symptoms for sufferers across the country.
Trending in April, May, and September
High blood pressure, or hypertension, is a primary risk factor for cardiovascular disease (heart disease and stroke)—the leading cause of death in the United States. Antihypertensives, aka blood pressure medications, help keep it under control to reduce the likelihood of these serious health problems. A third of all adults over age 20 with hypertension take these medications to reduce blood pressure. There are many different types of blood pressure medications available. Lisinopril, an ACE inhibitor, is the most prescribed—followed by losartan potassium and clonidine—according to SingleCare data. “A possible reason for this spike during the months of April/May and September may be due to 90-day fill cycles,” suggests Dr. Uche. “Insurance companies may authorize a 90-day supply on chronic medications for cost reasons and patient convenience.”
The rise in prescriptions “overlaps with the allergy seasons in the spring and fall,” says Dr. Shaukat. “Anti-allergy medications include anti-congestant medications like phenylephrine and pseudoephedrine. The side effects of these include vasoconstriction, which will cause a rise in blood pressure. It’s best to use other medications that do not cause an increase in blood pressure if you are already diagnosed with hypertension.” Your pharmacist is a great resource if you need help selecting a product that is compatible with other medical conditions you have.
Additionally, the amount of medication you need to manage hypertension may vary depending on the time of year. Research shows that blood pressure changes seasonally. It’s lower in the summer, and higher in the winter, with some evidence that blood pressure is lowest when temperatures are the highest. This could explain why antihypertensives are the most popular prescription drug class during the moderate temperature times of the year. Blood pressure starts to creep up at the end of the summer, or people notice high blood pressure readings after winter, and seek medication as spring approaches.
Trending in June, July, and August
Dermatologicals are a type of medication that treat skin conditions, such as rashes, eczema, and psoriasis. They can also treat bacterial or fungal skin problems, hair loss, or pain from arthritis. In the summer months of June, July, and August, fills of these treatments soar.
In the hotter weather, people have more skin exposed and spend more time outdoors. As the layers come off, people with skin conditions might feel more self conscious about red, flaky patches, and more aggressively treat them. Or, all of that time spent hiking leads to more rashes and body pain. “Sweat during the summer months can contribute to an increase in acne, as a result medications like mupirocin and tretinoin are used to combat this,” says Dr. Shaukat. “Other topical gels like diclofenac are used to aid in aches and pains related to musculoskeletal complaints as we all get out and moving, contributing to more musculoskeletal injuries in the summer months.” Additionally, if you’re spending a lot of time escaping the heat in air conditioning, the “low humidity during the summer months may lead to drying of the skin and nasal passages sparking dermatological conditions,” says Dr. Uche.
Another factor to consider? By summertime, many people have met their insurance deductible for the year. At that point, “out-of-pocket costs are significantly reduced,” explains Dr. Uche. “Since medical costs are now more affordable, seeking medical assistance for dermatological conditions, especially if they are non-threatening or cosmetic, becomes more practical.”
The top dermatological agent in the summer months is triamcinolone, a corticosteroid that treats rashes and allergic reactions (possibly from that poison ivy you ran into on the trail), and also conditions like psoriasis. Next up is mupirocin, an antibiotic ointment for skin infections like folliculitis that can be caused by wearing sweaty clothes or dipping into hot tubs. They’re closely followed by finasteride (in pill form, a baldness treatment), diclofenac sodium (a topical gel that can treat pain and inflammation), and tretinoin (a common acne treatment).
Trending in October
Experts recommend getting your flu shot by the end of October. It’s the best time to get the full benefits of the vaccination—allowing time to build immunity before peak season strikes mid-winter. The immunization is often available as early as August, but most people aren’t thinking about influenza as summer ends and back to school season begins. And many community vaccination drives don’t start until the end of September and beginning of October.
That’s because “flu vaccines are developed based on the previous year’s strains and in anticipation of suspected changes,” according to Dr. Uche. “These vaccines become available around October in time to be administered before the flu season. In this way the immune system has sufficient time to build up its defense, so if the virus is encountered, the body can fight it off effectively.”
That helps explain why in October, all of the top trending drugs are various forms of the flu vaccine: Flucelvax, Fluzone, and Afluria.
Antiasthmatic and bronchodilator agents
Trending in November
Fall and winter can be challenging seasons for people with allergies and respiratory problems, like asthma. For children, heading back to school means new allergen triggers, and exposure to viral infections from other kids that can exacerbate asthma. For adults, cold weather can make symptoms worse. And that can mean relying on antiasthmatic and bronchodilator agents more to help you breathe.
“November overlaps with the end of the fall allergy season and the beginning of the cold and flu season,” explains Dr. Shaukat. “Both of these contribute to an increased amount of post nasal drip, which contributes to wheezing and asthma exacerbations.”
These types of medications, available in inhalers and pill form, help to open airways and prevent wheezing. Combined, they add up to nearly a million fills. The most common are rescue (or quick relief) inhalers like Ventolin HFA, ProAir HFA, and generic albuterol HFA. They’re followed by the preventative medication montelukast sodium, the generic of Singulair, a tablet that decreases frequency of asthma attacks and need for rescue inhalers for people with severe asthma, exercise-induced asthma, or allergies.