
Cyclosporine: A strong oral immune-suppressing drug used in short bursts for severe eczema and psoriasis. It works faster than anything else, and blood pressure and kidney function set a hard limit on how long anyone stays on it. Dupixent: An injected biologic for moderate to severe eczema. It blocks two of the immune signals that drive the itch, and it is taken long term rather than as a course.


Choose for a fast, short burst of control in severe eczema or psoriasis while a longer-term treatment is set up.
Choose for moderate to severe eczema that creams can't control, as a long-term treatment without blood tests.
Can you take them together?
These are different paths for severe eczema. Cyclosporine is a short-term rescue; Dupixent is a long-term option. Cyclosporine is sometimes overlapped briefly while Dupixent starts working.
Compare uses by strength of evidence. Evidence level describes confidence in a benefit, not its size.











Inhibits calcineurin: Binds cyclophilin to block a T-cell activation switch. Reduces IL-2 signals: Limits a messenger that helps T cells become active. Calms skin inflammation: Overactive immune responses in skin decrease.
Cyclosporine binds cyclophilin; that complex inhibits calcineurin and T-cell cytokine production. This is a simplified skin-focused explanation of systemic immunosuppression.

Blocks IL-4 and IL-13 signals: Binds their shared receptor to interrupt these messages. Calms type 2 inflammation: Reduces immune signaling that drives eczema. Eases eczema and itch: Inflamed skin and itch improve as signaling falls.
Dupilumab binds IL-4 receptor alpha, inhibiting IL-4 and IL-13 signaling. Diagram focuses on atopic dermatitis; it does not show every approved indication or all downstream effects.
The dose is set by body weight, then adjusted by blood pressure and kidney tests, not by how the skin looks.
Starting dose: About 2.5 mg per kilogram of body weight a day, split into two doses. A severe flare may start around 4 to 5 mg per kilogram a day to get control quickly.
Going up: Raised in small steps every two to four weeks if response is poor, and only if the tests are stable.
Coming down: Once the skin is calm, the dose comes down in stages, to give the next treatment time to work.
Total course: Short by design. Many courses run 8 to 16 weeks. Guidelines advise no more than about a year of continuous treatment, less where possible.
There is no titration. The number is fixed by age and weight; the only variable is how often you inject.
Loading dose: Adults start with two 300 mg injections the same day at two different spots — 600 mg total. That front-loading reaches a working level quickly.
Usual dose: 300 mg every two weeks for adults. Adolescents 12 and over who weigh about 60 kg or more use the same schedule.
Children and smaller adolescents: Dose is set by weight, and the youngest children inject every four weeks rather than every two. Go by the prescription.
Going up: There is nothing higher. If it is not working at sixteen weeks, the conversation is about a different treatment, not a bigger dose.
Total course: Open-ended. This is maintenance, not a course — people stay on it for years when it works.
Twice a day, about 12 hours apart, at the same times daily. Be consistent about food: always with meals or always without, because switching changes absorption. Swallow capsules whole and leave them in the foil until you take them.
On the liquid, mix it with orange or apple juice in a glass cup, stir and drink it straight away, then rinse the cup with more juice and drink that too. Never use grapefruit juice.
Pick a day of the week and keep it. Take the pen or syringe out of the fridge 30 to 45 minutes ahead and let it warm to room temperature on its own — never in hot water, on a radiator, or in a microwave. A cold injection stings much more, and that one step explains most of the difference between people.
Inject into the front of the thigh or the abdomen, at least two inches from the navel. The upper arm works if someone else is injecting. Change the spot each time and avoid skin that is bruised, tender, scarred, or flaring. If the dose is two injections, give them one after the other in two different spots.
Take it when you remember unless the next dose is close, then skip it. Never take two at once. Tell the prescriber if you miss more than a dose or two, or vomit soon after taking it, because the dose is built around your blood level.
Give it as soon as you remember, as long as that is within about a week of the due day, then go back to your schedule. If longer than that, skip it and take the next on the usual day. Never double up to catch up. One missed injection does not undo months of treatment.
Cyclosporine is monitored more closely than any other skin drug, and that monitoring is why it can be used at all. Blood pressure is measured at every visit, often at home. Kidney function is checked by blood test, twice before starting for a reliable baseline, then every couple of weeks for a month or two, then monthly once the dose is steady. The same draws cover potassium, magnesium, uric acid, liver enzymes, blood counts and cholesterol. Drug blood levels are routine in transplant care, not usually needed at dermatology doses.
Two numbers drive the decisions. A rise in creatinine of about a quarter above your baseline, confirmed on a repeat test, means dropping the dose; about half means stopping. New high blood pressure means lowering the dose or adding a blood pressure medicine, and the choice matters: diltiazem and verapamil push levels up, amlodipine does not.
The interaction list is long. Drugs that raise levels include the azole antifungals, clarithromycin and erythromycin, and some HIV and hepatitis C medicines. Drugs that lower it include rifampin, phenytoin, carbamazepine and St John's wort. It also raises statin levels, so that dose is often reduced, and it interacts with colchicine, digoxin, methotrexate and potassium-sparing water tablets. Bring every prescription, supplement and herbal product to the first visit.
The time limit is the point of all this. Kidney damage builds with continuous use and part of it can be permanent, so guidelines cap continuous treatment at about a year and most dermatology courses are far shorter. Long or repeated use also raises the risk of skin cancer, lymphoma and serious infection, so skin checks continue afterward.
No routine blood tests are required — no liver, kidney, or blood count checks, which is a real advantage over the older systemic eczema drugs. Monitoring is a conversation about the skin, the itch, and the eyes.
Ask about the eyes at every visit. Conjunctivitis affects roughly one in ten people treated for eczema, more often with severe skin or eyelid involvement, and usually responds to lubricating drops or a short prescription course. Eye pain or changed vision goes to an eye doctor rather than being watched. Eosinophil counts rise in some people without causing anything, so a count taken for another reason should be read with that in mind.
Nothing builds up over the years, and there is no ceiling on how long you can stay on it. The recurring problem is insurance renewal, not safety.
Approximate windows, not promises.
First 2 weeksStarting: Itch settles first, often within days, and sleep improves. Tingling or burning in the hands and feet, headache and mild nausea are common early. Blood pressure and kidney tests get checked.
Weeks 2 to 6Working: Redness, weeping and thickness improve clearly. Chronic hives that antihistamines do not control usually settle within a month. Extra hair growth on the face, arms and body and swollen or tender gums start now; both are dose-related and reverse after stopping.
Weeks 8 to 16Plaque psoriasis: Large improvement, often near-clear at the higher end of the dose range. Usually where the course ends and another treatment takes over.
VariableSevere inflammatory ulcers: In pyoderma gangrenosum it stops the ulcer spreading while healing catches up. Response times differ a lot.
ThroughoutThe tests: Blood pressure creeping up and kidney numbers drifting decide whether the dose drops or the drug stops. Neither causes symptoms, which is why the tests are not optional.
First few minutesThe injection: A sting for a few seconds, then redness or aching. Common early, and it settles with later doses.
Weeks 1 to 2Itch lifts: Often within days, before anything shows in the mirror. The earliest and most reliable change.
Weeks 2 to 8Working: Sleep improves, scratching drops, and the skin looks calmer. Red or gritty eyes, if they happen, start here.
Weeks 12 to 16Judge it here: Trials measured their main result at sixteen weeks. Most responders reach their best skin here and a good number get close to clear; people only partly better at twelve often kept improving.
Weeks 12 to 24Sleep and daily life: These follow the itch, on a similar timeline, and trials measured them separately from the rash.
After 6 monthsThe face and neck: A stubborn pink patch appears here in a minority, usually after the rest of the skin has cleared. It is treatable and not a sign the drug has stopped working.
Sorted by what to do about them.
Generic capsules are cheap next to biologics, part of why the drug is still used. Branded versions cost more without working better.
The visible cost is not the whole cost. Repeated blood tests, blood pressure checks and appointments add up, and none are optional. It is cheaper per month than a biologic but taken for only a few months, so the comparison depends on what comes after.
Insurance generally covers it for severe psoriasis. Eczema coverage varies more in the United States, where that use is off-label.
Cost decides access here more often than anything medical. Dupilumab is a biologic with no generic and no biosimilar in the United States, and the list price runs to tens of thousands of dollars a year. Almost nobody pays that, and almost everybody has to do the paperwork that brings it down.
Prior authorization is close to universal. Plans want a diagnosis, a record of how much of the body is affected, and evidence that prescription topicals were tried and could not hold the disease — usually a mid- or high-strength steroid, often a calcineurin inhibitor too. Some add phototherapy or an older systemic drug first. First-pass denials are common and appeals often succeed, so a denial is a step, not the end. Ask the prescribing office who handles appeals.
The manufacturer's copay program cuts the monthly cost sharply for people with commercial insurance, and a separate program covers people with no insurance. Copay cards cannot be used with Medicare, Medicaid, or other government plans, which is where the largest out-of-pocket gaps sit. Terms change every year, so a plan that refused last year is worth asking again.
Faster than anything else for these conditions. Itch improves within days, clearing by four to six weeks.
Most courses run months. Guidelines cap continuous use at about one year, because kidney effects build and some can be permanent.
It raises blood pressure in a meaningful share of people, and that causes no symptoms. Catching it early usually means lowering the dose rather than stopping.
No. Grapefruit, pomelo and Seville oranges block the enzyme that clears it, so levels rise unpredictably. Other citrus is fine.
Both are dose-related. Not dangerous, usually better if the dose comes down, and gone after stopping.
Usually, within weeks to a few months, unless another treatment is running. Planning that before the taper is the point of the short course.
Itch often improves within two weeks. The skin takes longer — sixteen weeks is the fair point to judge.
It stings for a few seconds. Letting it reach room temperature first makes the biggest difference.
Roughly one in ten get red or gritty eyes, more often with severe eczema or eyelid involvement. Most settle with drops.
No routine tests, which is unusual for a drug of this kind.
Some people do, and some keep a good stretch. Eczema usually returns eventually, and restarting normally works.
Yes. Most people need far less, but flares still get topical treatment, and moisturizer continues indefinitely.