Albendazole Drug Interactions: Medicines, Foods, and Supplements to Avoid
Most people picture a dewormer as a simple, one-and-done pill. For a single dose against roundworm or pinworm, that picture is mostly right. But albendazole is also used for weeks or months at a time against tapeworm cysts in the liver, lungs, and brain, and over those longer courses, albendazole drug interactions can change how much active medicine reaches the parasite. Some drugs push levels up. Others pull them down so far that treatment may not work as well as planned.
This guide sorts the known and possible albendazole drug interactions into clear tables, explains the “why” behind each one, and finishes with a checklist you can bring to your pharmacist.
Safety note: This article is for education only and doesn’t replace advice from your prescriber or pharmacist. Never stop, start, or change the dose of any medicine on your own because of an interaction you read about online.
At a Glance
- Albendazole works mainly through its active metabolite, albendazole sulfoxide, which the liver makes quickly after each dose.
- The US label names three drugs that can raise sulfoxide levels: dexamethasone, praziquantel, and cimetidine.
- Strong enzyme inducers, such as phenytoin and long-term ritonavir, can lower levels sharply.
- The label advises monitoring theophylline levels during and after albendazole treatment.
- A fatty meal can raise sulfoxide levels up to about five-fold, which is why tissue infections are treated with food.
- Grapefruit and St. John’s wort are possible but less well-documented concerns. Ask before using either.
What’s in This Guide
- Why interactions matter for albendazole
- How to read the tables (severity legend)
- Medicines that raise albendazole levels
- Medicines that lower albendazole levels
- Drugs albendazole may affect
- Other medicines to discuss
- Food, grapefruit, and alcohol
- Supplements and herbal products
- Bring-this-list pharmacist checklist
- FAQ
Why Albendazole Drug Interactions Matter More Than You Might Think
Albendazole itself barely lingers in the bloodstream. After you swallow a tablet, the liver rapidly converts most of it into albendazole sulfoxide, the form that actually travels to tissues and attacks the parasite. That conversion step is the key to understanding interactions.
Laboratory studies point to two main enzyme systems doing this work: the cytochrome P450 enzyme CYP3A4 and a group called flavin-containing monooxygenases (FMOs). Other P450 enzymes then break the sulfoxide down further into an inactive sulfone. Anything that speeds up, slows down, or competes with these steps can shift how much active drug is circulating.
Absorption is already a weak link
Albendazole dissolves poorly in water, so only a small share of each dose gets absorbed from the gut. The FDA label notes that taking it with a fatty meal raised sulfoxide levels up to about five times higher than fasting. Because the starting point is so variable, an interaction that cuts levels further can matter a lot, especially when the target is a cyst deep in the liver or brain.
Course length changes the risk
Timing matters, too. Enzyme inducers usually need days of steady use before they ramp up liver enzymes. That means a person taking a single 400 mg dose for a gut worm faces a very different interaction picture than someone on repeated 28-day cycles for hydatid disease. If you’re not sure which type of treatment you’re on, our overview of what albendazole is prescribed for explains the main regimens.
Finally, albendazole has its own safety concerns, chiefly liver enzyme elevations and bone marrow suppression. Drugs that share those risks can stack on top of each other even without changing albendazole levels at all.
How to Read the Interaction Tables
Each table below uses a simple three-level legend. These ratings reflect how strong the evidence is and how much the interaction could change your care. They are not official FDA categories, and your pharmacist’s software may label things differently.
| Label | What it means | Typical action |
|---|---|---|
| Discuss first | Documented change in drug levels or overlapping toxicity that could affect results or safety | Prescriber may adjust the plan, add monitoring, or choose another drug |
| Monitor | Measurable effect that is usually manageable or expected | Often used together on purpose, with lab checks or symptom watch |
| Ask about it | Theoretical, based on mechanism, or supported by limited data | Mention it to your pharmacist so they can judge your situation |
One more point before the tables: “raises levels” is not automatically bad. In some cases doctors combine drugs precisely because the boost helps kill more parasites. The question is always whether the change is planned and monitored.
Table 1: Medicines That Raise Albendazole Sulfoxide Levels
The FDA prescribing information lists three medicines in this group. Each one was studied in a specific population, so the size of the effect may differ for you.
| Medicine | What the label reports | Why it happens | Rating |
|---|---|---|---|
| Dexamethasone (a corticosteroid) | Trough sulfoxide levels were roughly 56% higher in a small group of neurocysticercosis patients | Mechanism not fully clear | Monitor |
| Praziquantel (another antiparasitic) | In healthy volunteers taking a fatty meal, peak level and total exposure rose by about 50% | Possibly changes in absorption or transport | Monitor |
| Cimetidine (an acid reducer, brand Tagamet) | Sulfoxide concentrations in bile and cyst fluid were about twice as high in hydatid patients | Likely slows breakdown of the sulfoxide | Discuss first |
Dexamethasone: an intended partner in brain infections
For neurocysticercosis, the label tells prescribers to consider corticosteroids during the first week of treatment. As parasites die, the brain can swell, which may trigger headaches or seizures. Steroids calm that inflammation. The rise in albendazole levels is a side effect of this combination, not a reason to avoid it, and your care team already plans around it.
Praziquantel: sometimes combined on purpose
Specialists sometimes pair albendazole with praziquantel for certain cyst patterns in the brain. A randomized trial in neurocysticercosis patients found higher sulfoxide concentrations in the combination group, and researchers suggested this boost could add to the cyst-killing effect. Again, this is a specialist decision, not something to try on your own.
Cimetidine: the over-the-counter surprise
Cimetidine is the one people are most likely to take without telling anyone, since it’s sold on pharmacy shelves for heartburn. The data are mixed. The label describes higher levels in bile and cyst fluid, while a separate study in healthy volunteers found lower blood levels, possibly because reduced stomach acid hurts absorption. That inconsistency is exactly why it’s worth asking first. Other heartburn medicines also lower stomach acid, so mention any antacid or acid reducer you use.
Table 2: Medicines That Can Lower Albendazole Levels
Of all albendazole drug interactions, this group worries specialists most, because lower exposure may mean cysts survive treatment. The pattern is consistent: drugs that strongly switch on liver enzymes tend to clear albendazole and its sulfoxide faster.
| Medicine | What the evidence shows | Context | Rating |
|---|---|---|---|
| Phenytoin (seizure medicine) | A 2002 study in neurocysticercosis patients reported markedly lower albendazole exposure in people taking phenytoin | Seizure drugs are common in brain infections, so this overlap is real | Discuss first |
| Carbamazepine (seizure and nerve pain medicine) | Strong enzyme inducer; international albendazole labeling lists it as possibly reducing active metabolite levels | Same concern as phenytoin | Discuss first |
| Phenobarbital (seizure medicine) | Strong enzyme inducer; listed alongside phenytoin and carbamazepine in international labeling | Used less often today but still prescribed | Discuss first |
| Ritonavir (HIV medicine, also a booster in other regimens) | After 8 days of ritonavir, albendazole exposure in healthy volunteers dropped to roughly a quarter of baseline; two doses had no clear effect | Most relevant for long albendazole courses | Discuss first |
| Rifampin and other strong inducers | Not well studied with albendazole; concern is based on how these drugs act on liver enzymes | Theoretical, but worth flagging | Ask about it |
The seizure-medicine dilemma
Here’s the tricky part. People with neurocysticercosis often need seizure protection, yet several older seizure drugs reduce albendazole exposure. Researchers in Brazil studying these patients found substantially lower albendazole exposure in those taking older enzyme-inducing seizure drugs, and drug-interaction references describe the drop with phenytoin as roughly two-thirds. Product information used outside the US lists phenytoin, carbamazepine, phenobarbital, and ritonavir together as drugs that may reduce the active metabolite, while noting the clinical impact isn’t fully known.
Your neurologist and infectious disease doctor weigh this together. Options might include closer follow-up imaging, a different seizure medicine, or adjusting the albendazole plan. Not every seizure drug behaves the same way. For example, gabapentin is cleared mostly by the kidneys rather than liver enzymes; you can read more about it in our gabapentin vs. Lyrica comparison. Never switch or stop a seizure medicine without your prescriber, because a sudden stop can trigger dangerous seizures.
Ritonavir and other HIV regimens
A Swiss study published in the European Journal of Clinical Pharmacology gave healthy volunteers albendazole before and after ritonavir. Short-term ritonavir didn’t change much. After about a week, though, albendazole exposure fell dramatically. If you take ritonavir-boosted HIV medicine or another boosted regimen, tell your albendazole prescriber, especially before a multi-week course.
Albendazole speeds up its own clearance, too. The label notes that after four weeks of treatment, sulfoxide levels were about 20% lower than expected, suggesting the drug may gradually induce its own metabolism. Long courses already have built-in variability, which is one more reason to share your full medication list.
Table 3: Drugs Albendazole May Affect
Interactions can run both ways. In lab studies of human liver cells, albendazole switched on an enzyme called CYP1A. That enzyme breaks down several medicines, the best-known being theophylline.
| Medicine | Possible effect | What the label says | Rating |
|---|---|---|---|
| Theophylline (asthma and COPD medicine) | Levels could fall if albendazole speeds up its breakdown | A single 400 mg dose didn’t change theophylline levels in a study, but monitoring theophylline levels during and after treatment is recommended | Monitor |
| Other CYP1A2-cleared drugs (for example, some used for mental health or muscle spasm) | Theoretical decrease in levels | Not specifically studied | Ask about it |
Theophylline has a narrow safe range. Too little can bring back wheezing, and too much can cause nausea, a racing heart, or seizures. If you use it, your prescriber may order a blood level during a long albendazole course and again after you finish.
Table 4: Other Medicines to Discuss Before Starting
These aren’t classic level-changing interactions. Instead, they involve overlapping side effects. Because albendazole can raise liver enzymes and, rarely, suppress the bone marrow, the label calls for blood counts and liver tests at the start of each 28-day cycle and every two weeks during treatment. Adding other drugs with similar risks makes those checks even more important.
| Drug group | Examples | Shared concern | Rating |
|---|---|---|---|
| Medicines that can stress the liver | High-dose or frequent acetaminophen, certain antifungals, isoniazid, methotrexate, some cholesterol drugs | Added risk of liver enzyme elevations | Discuss first |
| Medicines that can lower blood counts | Chemotherapy, azathioprine, clozapine, some antithyroid drugs, certain antibiotics on long courses | Added risk of low white cells, platelets, or red cells | Discuss first |
| Other benzimidazole dewormers | Mebendazole | Same drug family; allergy to one means avoiding albendazole | Discuss first |
| Immune-suppressing drugs | Long-term steroids, transplant medicines | Harder to fight infections if counts drop | Monitor |
Acetaminophen deserves a quick word, because many people take it for headaches during treatment. Occasional use within label limits is generally considered reasonable, but it’s still worth confirming with your pharmacist. Our guide to oxycodone and Tylenol covers why total daily acetaminophen matters for the liver.
Watch for warning signs of low blood counts, such as fever, chills, or a sore throat that won’t quit. Those symptoms need a call to your prescriber rather than home care alone, even if a sore throat remedy would usually be your first move. For a full rundown of what to watch for, see our article on albendazole side effects.
Albendazole and Food: Fat, Grapefruit, and Alcohol
Food is the most powerful “interaction” most people will ever have with albendazole, and it can work in your favor or against your plan depending on what you’re treating.
| Food or drink | Effect | Evidence strength | Practical point |
|---|---|---|---|
| Fatty meal | Raises sulfoxide levels up to about 5-fold compared with fasting | Strong (FDA label; controlled studies) | Tissue infections: take with food as directed |
| Empty stomach | Keeps more drug in the gut | Guideline-based (CDC) | Some intestinal-worm regimens use this approach |
| Grapefruit juice | Raised sulfoxide levels about 3-fold in one small study | Limited | Ask before drinking it regularly |
| Alcohol | No direct level interaction documented; adds liver stress | Indirect | Discuss, especially on long courses |
Why fat helps for cysts but not always for gut worms
For hydatid disease and neurocysticercosis, the FDA label says to take albendazole with meals. A 2021 study in healthy adults found that a high-fat breakfast roughly doubled sulfoxide exposure compared with a low-fat one. More absorption means more drug reaching the cyst.
For worms living inside the intestine, the goal is different. CDC treatment guidance for roundworm, hookworm, whipworm, and pinworm describes taking albendazole on an empty stomach, which keeps more of the drug in the gut where these worms live. Follow the instructions on your own prescription label, since your prescriber chose them for your infection.
Grapefruit: real signal, thin data
Grapefruit is famous for blocking CYP3A4 in the gut wall. With albendazole, a small study in six healthy men found that double-strength grapefruit juice raised sulfoxide levels about three-fold. Interestingly, the researchers noted the effect may not come purely from enzyme blocking. Six people is far too few to draw firm conclusions, and the US label does not list grapefruit. Still, some hospital pharmacy leaflets advise avoiding it. The safest path is to ask your pharmacist and keep your intake consistent rather than suddenly drinking large amounts.
Alcohol
No study shows alcohol changing albendazole levels directly. The concern is overlap: both can strain the liver, and heavy drinking can affect blood counts over time. We cover this question in depth in can you drink alcohol while taking albendazole, including how the answer differs for a single dose versus a long course.
Supplements and Herbal Products That May Interact With Albendazole
Very few supplements have been tested alongside albendazole. That doesn’t mean they’re safe; it means nobody has measured. The table below is based mostly on how these products affect drug-processing enzymes in general.
| Product | Possible concern | Evidence basis | Rating |
|---|---|---|---|
| St. John’s wort | Could lower albendazole levels by inducing CYP3A4 | Theoretical; St. John’s wort is a well-documented CYP3A4 inducer with other drugs, but no albendazole study | Ask about it |
| Ginseng | Some pharmacy leaflets advise avoiding it during treatment | Limited | Ask about it |
| Herbal liver “detox” blends, kava, high-dose green tea extract | Possible added liver stress | Based on known liver-injury reports for some products | Ask about it |
| “Natural” antiparasitic blends | Unknown ingredients; may delay proper treatment | Not studied | Ask about it |
St. John’s wort deserves special mention. It’s known to induce CYP3A4 and the transporter P-glycoprotein, which lowers levels of many medicines. Since CYP3A4 is involved in albendazole metabolism, a drop in effect is plausible, though unproven. If you take it for mood, don’t stop abruptly without talking to your prescriber.
Concentrated green tea extracts have occasionally been linked to liver injury. Brewed tea in normal amounts is a different matter, and our piece on green tea discusses that distinction. During a long albendazole course, though, it’s wise to pause any high-dose extract until you’ve checked with your pharmacist.
Special Situations That Change the Interaction Picture
Liver disease
Because the liver does almost all the work of processing albendazole, people with liver problems may handle it differently. The label notes that patients with liver abnormalities before treatment may be at higher risk for bone marrow problems and need closer monitoring. Any interaction becomes more significant in this setting.
Pregnancy and birth control
Albendazole may harm a developing baby, and the label recommends effective contraception during treatment and for three days after the last dose. No interaction with hormonal birth control is described in the label. If you’re on any enzyme-inducing drug, though, ask whether your birth control method is still reliable, since those drugs can affect hormonal contraceptives. Our guide to albendazole during pregnancy and breastfeeding goes into the details.
Smoking changes
Some interaction databases flag nicotine and smoking, because tobacco smoke also induces CYP1A2. If you quit or cut back during a long course, mention it to your prescriber. Quitting is still a great idea; it’s just one more variable to share.
Missed or doubled doses
Doubling up to “catch up” is a different kind of risk. It raises levels in the same way an inhibitor might. If a dose slips, follow the guidance in what to do after a missed albendazole dose rather than taking two at once.
Bring This List to Your Pharmacist
Pharmacists catch albendazole drug interactions best when they see the full picture. Before your first dose, write down or photograph everything you take, then walk through this checklist together.
My albendazole interaction checklist
- What infection is this for, and how long will I take albendazole?
- Should I take it with a fatty meal or on an empty stomach?
- Do I take any seizure medicine (phenytoin, carbamazepine, phenobarbital, or others)?
- Do I take ritonavir, a boosted HIV regimen, or rifampin?
- Do I use cimetidine, other acid reducers, or antacids?
- Will I also be on dexamethasone or praziquantel as part of this plan?
- Do I take theophylline or another drug with a narrow safe range?
- Do any of my medicines affect the liver or blood counts?
- What supplements, herbs, teas, or “cleanse” products do I use?
- How much grapefruit and alcohol do I usually have?
- Could I be pregnant, and is my birth control affected by any of these drugs?
- When are my blood tests, and who should I call with symptoms?
Using one pharmacy for all your prescriptions helps, because its system can flag combinations automatically. If you fill prescriptions at more than one place, bring your list each time.
When to get help right away
Call 911 for a seizure, trouble breathing, swelling of the face or throat, or confusion. For a suspected overdose or accidental ingestion, especially by a child, contact Poison Control at 1-800-222-1222 or use poisonhelp.org. Call your prescriber promptly for fever, unusual bruising, yellow skin or eyes, dark urine, or severe stomach pain.
Albendazole Interactions: Frequently Asked Questions
What should I avoid while taking albendazole?
There’s no single “never take” list for everyone. The main medicines to discuss are seizure drugs like phenytoin and carbamazepine, ritonavir, cimetidine, and theophylline. It’s also wise to ask about grapefruit, St. John’s wort, heavy alcohol use, and other drugs that affect the liver or blood counts.
Can I take ibuprofen or acetaminophen with albendazole?
Neither is listed as a key interaction in the US label. Many people use one of them for headaches during treatment. Because albendazole can affect the liver, ask your pharmacist about acetaminophen limits, and check whether ibuprofen suits your stomach and kidney health.
Does albendazole interact with birth control pills?
The label doesn’t describe an interaction between albendazole and hormonal birth control. It does recommend effective contraception during treatment and for three days afterward. If you also take an enzyme-inducing drug, ask whether your method stays reliable.
Why is dexamethasone given with albendazole if it raises levels?
In brain infections, dying parasites can cause swelling and seizures. Steroids reduce that inflammation. The modest rise in albendazole levels is expected and is part of a planned, monitored regimen.
Is grapefruit really a problem with albendazole?
One small study found grapefruit juice raised albendazole sulfoxide levels about three-fold. The evidence is limited, and the US label doesn’t mention it. Ask your pharmacist, and avoid big changes in how much you drink during treatment.
Do interactions matter for a single dose?
Generally less. Many albendazole drug interactions involve inducers that need days to change enzyme activity. A one-time dose for a gut worm carries a smaller interaction risk than a multi-week course. Still, tell your pharmacist about every medicine you take.
Can I take antacids with albendazole?
Stomach acid helps albendazole dissolve, so drugs that reduce acid could, in theory, affect absorption. Data are mixed. Ask your pharmacist whether to space them apart or pause them during treatment.
Should I stop my seizure medicine to make albendazole work better?
No. Stopping seizure medicine suddenly can cause serious seizures. Your care team will decide whether to adjust either drug and how to monitor your response.
Putting It Together
Albendazole drug interactions mostly come down to one idea: anything that changes how the liver makes or clears albendazole sulfoxide can change how well treatment works. Dexamethasone, praziquantel, and cimetidine can push levels up. Phenytoin, carbamazepine, phenobarbital, and long-term ritonavir can pull them down. Food, especially fat, is the biggest lever of all.
For a single dose, the risk is usually low. For a long course against cysts, every medicine, supplement, and habit is worth discussing. Bring your list, ask your questions, and keep your blood-test appointments. That simple routine catches most problems before they start.
Sources
- DailyMed (NIH): Albendazole tablets prescribing information
- MedlinePlus: Albendazole
- CDC: Clinical Care of Soil-Transmitted Helminths
- Corti N, et al. Effect of ritonavir on the pharmacokinetics of albendazole and mebendazole. European Journal of Clinical Pharmacology
- Ochoa D, et al. High-fat breakfast increases bioavailability of albendazole. Frontiers in Pharmacology, 2021
- University of Liverpool HIV Drug Interactions: Albendazole
- Dürr D, et al. St John’s wort induces intestinal P-glycoprotein and CYP3A4. Clinical Pharmacology & Therapeutics (PubMed)
Medical disclaimer: This content is provided for general educational purposes and is not a substitute for professional medical advice, diagnosis, or treatment. Drug interaction information changes as new research appears, and individual factors such as liver health, other conditions, and the full medicine list affect risk. Always consult your prescriber or pharmacist before starting, stopping, or combining medicines. If you think you’re having a medical emergency, call 911.
