Phosphodiesterase-4 (PDE-4) inhibitors are specialty drugs doctors prescribe to treat mild to severe plaque psoriasis. They work by lowering and managing inflammation, the underlying cause of flare-ups on your skin, as well as certain lung diseases.
But PDE-4 inhibitors aren’t for everyone with psoriasis. Here’s how they work, who they’re best for, and how to get a prescription.
How Do PDE-4 Inhibitors Work in the Body?
Inflammation is the underlying cause of many diseases in your body, including diseases like psoriasis. But what triggers inflammation?
Your body makes an enzyme called phosphodiesterase-4 or PDE-4. PDE-4 gets in the way of a chemical reaction called cyclic adenosine monophosphate (cAMP). This interference raises the inflammation in your body. Your skin responds by speeding up the skin cell growth of plaque psoriasis.
PDE-4 inhibitors block the production of PDE-4. Blocking PDE-4 raises cAMP activity and lowers inflammation.
Who Should Take PDE-4 Inhibitors?
Treatment for plaque psoriasis typically starts with medicines you spread on your skin, called topical treatments. Often these are steroids. Your doctor may also prescribe phototherapy (UV light on the skin). Topical treatments and phototherapy attack inflammation in the skin itself.
If these treatments don't work well or if your plaque psoriasis is moderate to severe, your doctor may prescribe a PDE-4 inhibitor like apremilast (Otezla). Your provider may also ask you to combine apremilast with a topical treatment, phototherapy, or other treatments such as methotrexate.
In clinical studies, researchers treated people with mild psoriasis using apremilast and had good results. Talk to your doctor about whether you should try apremilast for mild psoriasis.
Two topical PDE-4 inhibitors may become available for psoriasis in the near future. Roflumilast is showing promise in clinical trials. Crisaborole is another potential PDE-4 inhibitor option doctors currently use for atopic dermatitis.
Who Shouldn't Take PDE-4 Inhibitors?
PDE-4 inhibitors are for adults only. Your doctor may not recommend them if any of the following apply to you:
- You’re elderly and have low blood pressure or low blood volume.
- You take certain medications.
- You have depression or a history of mental illness.
- You’re pregnant, planning to get pregnant, or breastfeeding.
- You have kidney disease.
How Do You Get PDE-4 Inhibitors?
PDE-4 inhibitors like apremilast are not available at regular retail pharmacies. Your doctor will send your prescription to a specialty pharmacy. Specialty pharmacies provide medications to treat serious or rare health conditions.
Your specialty pharmacy will work with you and your insurance company. If you don’t have insurance, the specialty pharmacy may also help you get financial aid to pay for your prescription. Once your prescription is ready, the pharmacy will work with you to set up a delivery day.
What Can You Expect When You Get Your Prescription?
Apremilast is a 30-milligram pill you take twice a day. To lower the risk of side effects, you’ll start by taking 10 milligrams the first day. Over the next few days, you’ll increase to 20 milligrams, then 30 milligrams. As you increase the dosage, you should keep track of side effects and let your doctor know about them.
What Are the Side Effects of PDE-4 Inhibitors?
The FDA considers PDE-4 inhibitors safe and effective. But like most medications, these drugs cause side effects.
Common side effects of PDE-4 inhibitors include:
- Abdominal pain
- Weight loss
- Upper respiratory tract infections
How Much Do PDE-4 Inhibitors Cost?
Apremilast is the only approved oral PDE-4 inhibitor for the treatment of psoriasis. The list price for a 30-day supply is $3,950. How much of this you will pay depends on your health plan.
Here’s a breakdown of possible costs:
Commercial insurance. If you have a commercial insurance plan, you can get apremilast for $0 a month using a special co-pay card. You can get your card by enrolling in a program.
If your health plan doesn’t cover apremilast or asks for preauthorization, you can still get the medication for free for up to 12 months. This will give you time to work with your insurer and get them to approve your medication.
Medicare/Medicaid. If you’re on Medicare or Medicaid, you can connect with the Amgen Safety Net Foundation. The foundation has a patient assistance program that may help you get your prescription for free.
No insurance. The Amgen Safety Net Foundation also helps people without health insurance get apremilast for free.
Talk to Your Doctor
PDE-4 inhibitors may help you manage psoriasis, but they’re not for everyone. You might need to try other medications first, or you might need to combine them with other medications.
Talk to your doctor about taking PDE-4 inhibitors. They can tell you if PDE-4 inhibitors are right for you based on your health history and your current psoriasis condition.