Short answer: Several common medications that raise white blood cell count are well documented. MedlinePlus, the National Library of Medicine's consumer health service, lists corticosteroids (such as prednisone), lithium, epinephrine, beta agonists like albuterol, heparin, and granulocyte colony-stimulating factor (G-CSF). Cigarette smoking, surgery to remove the spleen, pregnancy and severe physical or emotional stress can raise the count too. A raised number on its own is a clue, not a diagnosis, and the clinician who ordered the test is the person who can say which explanation fits.
A laboratory report should not create fear. It should create understanding. This guide explains what each of these influences does to a complete blood count (CBC), why doctors look at the pattern rather than the single number, and which signs mean a result needs attention now rather than at the next appointment.
When a high WBC needs attention now
Before the explanations, here is the part that matters most if you are reading this with a fresh result in hand.
MedlinePlus, in its guide to when adults should use the emergency room (reviewed September 2024), lists symptoms such as severe shortness of breath, severe chest pain or pressure, fainting, sudden confusion, heavy bleeding, and high fever with a stiff neck as reasons to call 911 or go to an emergency department. None of those should wait for a lab explanation, whatever medicine is involved.
For a raised count without an emergency, the American Academy of Family Physicians review "Evaluation of Patients with Leukocytosis" (Riley and Rupert, American Family Physician, 2015; read on 2026-09-23) lists features that point away from a simple medication or lifestyle effect and toward a possible bone marrow problem that needs prompt specialist review:
- Red blood cell or platelet counts that are also abnormal
- A white count above 30,000 per microliter
- Fever, night sweats or unintentional weight loss
- Easy bruising or bleeding
- Swollen lymph nodes or an enlarged spleen
When these features appear alongside a high white count, the AAFP review describes prompt referral to a hematologist as the expected step. That is a conversation to have with the ordering clinician soon. It is not a reason to panic, and it is not something a medication list can explain away.
Why medications and habits change the WBC at all
A standard blood draw counts only the white cells circulating at that moment. It does not count cells held in reserve in the bone marrow, and it does not count neutrophils resting against the walls of blood vessels, which a classic Annals of Internal Medicine review of steroid therapy (Fauci and colleagues, 1976) describes as a separate pool that steroids can shift into circulation.
That detail explains most drug effects. According to the AAFP review, the medications on this list raise the count largely by releasing neutrophils the body already has, from marrow reserves, into the bloodstream. Nothing new is attacking the body. The cells have simply moved into the part of the blood a lab can see.
This is why a medication-related rise is usually described as "reactive": it reflects a response to something outside the bone marrow, not a problem inside it. Our guide to how doctors tell reactive from serious high WBC goes deeper on that distinction, including the tests that separate the two.
Medications that raise white blood cell count, one by one
The table below brings together what two authoritative sources say. The MedlinePlus WBC count test page (reviewed February 2025; read on 2026-09-23) lists these drugs as ones that may increase a WBC count, and the AAFP review lists the same core group in its table of neutrophilia causes.
| Medication or group | Common settings | What the sources say |
|---|---|---|
| Corticosteroids | Asthma flares, arthritis, allergic reactions, autoimmune conditions | Listed by MedlinePlus and AAFP; raise mainly neutrophils |
| Lithium | Bipolar disorder | Listed by both as a cause of a raised count |
| Beta agonists (for example albuterol) | Asthma and COPD inhalers or nebulizers | Listed by both |
| Epinephrine | Severe allergic reactions, emergency care | Listed by both; AAFP describes release of stored neutrophils |
| G-CSF (colony-stimulating factors) | Some cancer care, to raise low neutrophil counts | Intended to increase white cells; listed by both |
| Heparin | Blood thinner, often in hospital | Listed by MedlinePlus |
A few notes on each, kept to what the sources support.
Corticosteroids
Prednisone, methylprednisolone, dexamethasone and hydrocortisone all belong to this group, which is prescribed across a wide range of conditions. The 1976 Annals review described the steroid pattern as a rise in neutrophils together with falls in lymphocytes and eosinophils. That signature matters, and we return to it below.
Lithium
Lithium is a long-standing treatment for bipolar disorder, and both MedlinePlus and the AAFP name it among drugs that raise the WBC. For someone on it long term, a mildly high count may show up on more than one test. Only the prescribing clinician can say whether a given result fits that picture.
Beta agonists and epinephrine
Albuterol and injected epinephrine both appear on the MedlinePlus and AAFP lists. The AAFP review groups their effect under catecholamine-driven release of stored neutrophils, which is why a count drawn during or just after an asthma attack or an allergic reaction can read higher than it otherwise would.
G-CSF and other colony-stimulating factors
These are the one group on the list prescribed specifically to raise the count. Filgrastim and related drugs are used in some cancer care, where a very low neutrophil count is the concern. A high count in someone receiving them may be the intended effect, and their care team tracks it. If your question is really about a count that is too low, our guide to low WBC count causes is the better starting point.
Heparin
MedlinePlus includes heparin on its list. It is mostly given in hospital, so it tends to come up when a CBC is drawn during an admission rather than at a routine checkup.
A reminder that matters: none of this is a reason to start, stop or change any medicine. Only the prescriber can weigh a lab result against the reason a drug was chosen.
Smoking, stress and the other non-drug influences
MedlinePlus lists several non-medication causes of a high WBC alongside the drugs:
- Cigarette smoking. Named by both MedlinePlus and the AAFP. It is one of the reasons clinicians ask about smoking when a count sits a little high.
- Severe emotional or physical stress. MedlinePlus lists both.
- Surgery to remove the spleen. MedlinePlus lists the period after splenectomy as a cause of a higher count.
- Pregnancy. Also on the MedlinePlus list.
- Inflammatory disease, tissue damage such as burns, and infection, most often bacterial, per MedlinePlus.
The AAFP review adds obesity to its list of acquired causes. Neither source gives a fixed amount of rise for any of these that applies to everyone, so we have not put numbers on them here.
The part most lists skip: the pattern, not the number
Most pages on this topic stop at a list of drug names. The question that actually helps is this: does the shape of the result fit the explanation?
A single total WBC cannot tell a steroid effect from an infection. The differential, which breaks the total into neutrophils, lymphocytes, monocytes, eosinophils and basophils, often can. Our guide to the WBC differential, cell by cell explains each line of that report.
Here is how the sources describe the patterns clinicians look for:
| What the report shows | What it can fit, per the sources above |
|---|---|
| High neutrophils, low lymphocytes and low eosinophils, other counts normal | The steroid pattern described in the 1976 Annals review |
| Mildly high count in someone who smokes or takes lithium | A reactive rise among the causes MedlinePlus and AAFP list |
| High white count with abnormal red cells or platelets | One of the AAFP features that prompts specialist review |
| Count above 30,000 per microliter | Also on the AAFP list for prompt referral |
| High lymphocytes rather than neutrophils | A different set of causes than the drugs above |
The AAFP review says the first step after an unexpected high count is a repeat CBC with a differential and a review of a blood smear under the microscope. That repeat test, read alongside the medication list, is often what settles the question.
What a medication explanation cannot do
It is worth being honest about the limits here.
- A drug on the list does not rule anything out. Someone on prednisone can also have an infection. The AAFP review notes that a reactive rise typically falls between about 11,000 and 30,000 per microliter, a range that many causes share.
- Reference ranges vary by lab. MedlinePlus gives a normal range of 4,500 to 11,000 white cells per microliter and notes that normal ranges can vary slightly between laboratories. The range printed on your own report is the one that applies to your result.
- One result is a snapshot. A count reflects the moment it was drawn, which is one reason the AAFP review starts with a repeat CBC to confirm the finding.
- Only the ordering clinician has the full picture. They know the dose, the timing, your symptoms, your history and your earlier results. A list on the internet does not.
Our overview of whether a high white blood cell count always means infection walks through the wider set of causes if your report does not fit the medication story.
Details worth bringing to your appointment
These are details to gather, not a treatment plan. They help the ordering clinician read the result in context:
- Every medicine, inhaler and injection used in the weeks before the test, including short steroid courses and emergency epinephrine.
- Whether you smoke, and how much.
- Any recent illness, surgery, hard exercise or major stress.
- Whether earlier CBCs showed a similar number.
- Which cell type on the differential is actually high.
Questions worth asking in return: Does this pattern fit my medication? Would a repeat CBC help? Is there anything on the report besides the white count that needs a closer look?
Frequently asked questions
Which medications raise white blood cell count?
MedlinePlus lists corticosteroids, lithium, epinephrine, beta agonists such as albuterol, heparin and G-CSF. The AAFP's 2015 leukocytosis review names the same core group in its table of causes.
Can prednisone make my WBC look like an infection?
It can raise the total count, which is why doctors look at the differential. A 1976 Annals of Internal Medicine review described steroids as raising neutrophils while lowering lymphocytes and eosinophils. Only the ordering clinician can say whether a given pattern fits a steroid effect or something else.
Does smoking raise white blood cell count?
MedlinePlus and the AAFP both list cigarette smoking as a cause of a higher WBC. Neither gives a single figure that applies to everyone, so it is one factor a clinician weighs, not a complete explanation on its own.
How high is too high for a medication effect?
The AAFP review describes reactive rises as typically between about 11,000 and 30,000 per microliter. It lists a count above 30,000, abnormal red cells or platelets, fever, night sweats, weight loss, easy bruising or swollen lymph nodes as reasons for prompt specialist review. The normal range on your own report may differ by lab.
Should a medicine change because the white count is high?
That decision never comes from a lab number alone. It belongs to the prescriber, who can weigh the result against why the drug was chosen and what else the report shows.
The bottom line
A list of medications that raise white blood cell count is a useful starting point, not an answer. Steroids, lithium, albuterol, epinephrine, heparin and G-CSF are all documented causes, and smoking, stress, pregnancy and spleen removal can do the same. What turns a number into understanding is the pattern on the differential, a repeat test when needed, and a conversation with the clinician who ordered it. Any of the warning signs above, or any emergency symptom, changes the timeline from "next appointment" to "now".
