Last reviewed: October 2026
Heartburn boxes rarely say “baking soda” on the front. They say “fast relief,” “extra strength,” or “fizzy,” and the ingredient that matters most to someone on Evekeo sits in small print on the back. That’s why this guide to Evekeo and antacids works a little differently. Instead of a list of brand names to avoid, it teaches you how to turn a package over, find the active ingredient, and work out whether that ingredient pushes your stomach or urine toward the acidic or the alkaline side, which is the thing the Evekeo labels actually talk about.
Evekeo is racemic amphetamine sulfate, a 1:1 mix of dextroamphetamine and levoamphetamine. It comes as a standard immediate-release tablet and as Evekeo ODT, an orally disintegrating tablet. Both are Schedule II controlled substances and carry a boxed warning about abuse, misuse, and addiction. Nothing here replaces your prescriber’s or pharmacist’s advice, and nothing here is a reason to change how you take your dose. The goal is to help you ask sharper questions.
What the clues add up to
- The label’s concern is pH, not “antacids” as a category. Both Evekeo labels describe acidifying agents as lowering amphetamine levels and alkalinizing agents as raising them.
- Sodium bicarbonate is the one antacid ingredient the labels name. It’s the headline ingredient in Alka-Seltzer-type fizzy tablets and it also hides in many effervescent vitamin packets.
- Calcium carbonate and magnesium or aluminum hydroxide are not named. The Evekeo tablet label uses “etc.” after sodium bicarbonate, so it’s reasonable to ask your pharmacist how regular use of these fits your routine.
- Neither Evekeo label mentions proton pump inhibitors (PPIs). MedlinePlus’s general amphetamine page does list omeprazole, esomeprazole, and cimetidine among medicines to tell your doctor about.
- Prescription urinary alkalinizers matter too. Potassium citrate, acetazolamide, and some thiazide diuretics change urine pH, and the labels address that route separately.
- Evekeo ODT needs no water, but the label says it can be taken with or without food or liquid. What you sip it with is a fair question for the pharmacist.
Why Evekeo cares about pH
Amphetamine is a weak base. In a more acidic setting, more of the molecules carry an electrical charge (the “ionized” form). In a more alkaline setting, more of them stay uncharged. That difference matters in two places along the drug’s path.
The first is the gut, where uncharged molecules cross into the bloodstream more readily. The second is the kidney, where charged molecules get trapped in urine and flushed out, while uncharged molecules are more easily reabsorbed back into the blood. Shift the pH toward alkaline in either place and more amphetamine tends to stay in circulation. Shift it toward acidic and less does.
The Evekeo ODT label puts a number on the kidney side. In its pharmacokinetics section it describes amphetamine as renally eliminated “in a pH-dependent manner,” with roughly 70% excreted unchanged at a urine pH of 6.6 compared with 17% to 43% when urine pH is above 6.7. The same section lists average elimination half-lives of about 10.0 hours for d-amphetamine and about 11.7 hours for l-amphetamine in healthy adults. Because Evekeo contains a meaningful share of the l-isomer, unlike dextroamphetamine-only products, it has two half-lives to think about, which is one of the differences covered in our Evekeo vs. Adderall comparison.
What the Evekeo tablet label says, in its own terms
The Evekeo tablet prescribing information on DailyMed (revised June 2025) is an older-style label. Its drug interaction section sorts things into four buckets:
- Gastrointestinal acidifying agents, with examples given as guanethidine, reserpine, glutamic acid HCl, ascorbic acid, and fruit juices. These lower absorption.
- Urinary acidifying agents, with examples given as ammonium chloride and sodium acid phosphate. These increase the ionized form and raise urinary excretion.
- Gastrointestinal alkalinizing agents, with sodium bicarbonate as the example followed by “etc.” These increase absorption.
- Urinary alkalinizing agents, with acetazolamide and “some thiazides” as examples. These increase the non-ionized form and decrease urinary excretion.
The label then sums up each side: both acidifying groups lower blood levels and efficacy, and both alkalinizing groups raise blood levels and can strengthen amphetamine’s action. It does not mention proton pump inhibitors or H2 blockers at all, and it doesn’t give a spacing rule for antacids.
What the Evekeo ODT label says
The Evekeo ODT label on DailyMed (last revised April 2024) uses the newer table format. In its dosing section it notes that agents that change urinary pH can alter amphetamine blood levels, with ascorbic acid given as an acidifying example and sodium bicarbonate as an alkalinizing one. Its interaction table then says:
- Alkalinizing agents may increase exposure to amphetamine and intensify its action. The label advises caution when Evekeo ODT is combined with gastrointestinal and urinary alkalinizing agents.
- Acidifying agents lower blood levels and efficacy. The label’s instruction here is directed at the prescriber, who may adjust the dose based on clinical response. That’s a prescriber’s call, not something to try at home.
Like the tablet label, the ODT label has no row for proton pump inhibitors. That’s worth knowing because some other amphetamine products do address PPIs directly. If you’ve read our Adderall and antacids guide, you’ll have seen PPI wording that simply doesn’t appear on either Evekeo label. Don’t carry another product’s rules over to Evekeo, and don’t assume the silence means “no effect.” It means the label doesn’t say.
Same caution for all three uses
The Evekeo tablet is labeled for three uses: narcolepsy, ADHD as part of a total treatment program, and exogenous obesity as a short-term adjunct (a few weeks) to a calorie-restricted weight-reduction plan. Evekeo ODT is labeled only for ADHD in patients 6 to 17 years old. The pH interaction comes from the drug’s chemistry, so it applies whichever reason the medicine was prescribed for.
Reading the label like a detective: Evekeo and antacids, box by box
Every over-the-counter medicine sold in the US carries a standardized Drug Facts panel, and the first line is always “Active ingredient(s)” with an amount and a purpose. Supplements use a Supplement Facts panel instead, with a separate “Other ingredients” line underneath. Those two spots are where your evidence lives. The marketing on the front of the box tells you what the product wants to be known for. The back tells you what’s actually in it.
A three-step habit covers almost everything:
- Find every active ingredient. Many heartburn products combine two or three.
- Scan the “other” or inactive ingredients on fizzy or dissolvable products, where bicarbonate often shows up as a helper ingredient rather than the star.
- Ask which way it pushes pH, and in which place (stomach or urine). Then match that to the Evekeo label’s buckets.
Here are six cases you’re likely to run into.
Case 1: The fizzy tablet (sodium bicarbonate in effervescent products)
The clue: “Sodium bicarbonate” in the active ingredients, usually listed as an antacid, often alongside citric acid. Alka-Seltzer Original is the classic example. Its Drug Facts panel lists aspirin 325 mg, heat-treated sodium bicarbonate 1,916 mg, and anhydrous citric acid 1,000 mg per tablet, with directions to dissolve the tablets fully in water before drinking.
What it means: This is the exact ingredient both Evekeo labels use as their alkalinizing example. When the tablet dissolves, citric acid and bicarbonate react (that’s the fizz), but these products are formulated so that plenty of bicarbonate is left over to neutralize stomach acid. So the label’s wording about gastrointestinal alkalinizing agents applies most directly here.
The second clue on the same box: Original Alka-Seltzer also contains aspirin, which brings its own concerns (stomach bleeding, blood thinner interactions). Other versions in the brand family use different ingredients. Only the Drug Facts panel tells you which one you’re holding.
Plain baking soda counts too. A spoonful of kitchen baking soda in water is sodium bicarbonate, and MedlinePlus’s amphetamine page lists sodium bicarbonate products by name among medicines to tell your doctor about.
Case 2: The chewable (calcium carbonate, sometimes with magnesium hydroxide)
The clue: “Calcium carbonate” as the active ingredient, purpose “antacid.” Tums is the familiar brand, sold in strengths labeled 500, 750 (Extra Strength), and 1,000 mg (Ultra Strength). Rolaids often lists two antacids. One Rolaids product on DailyMed, for example, contains calcium carbonate 1,000 mg and magnesium hydroxide 200 mg per tablet, plus simethicone for gas.
What it means: These are bases that neutralize stomach acid, so in chemistry terms they belong on the alkaline side of the ledger. But here’s the honest part of the investigation: neither Evekeo label names calcium carbonate or magnesium hydroxide. The tablet label lists sodium bicarbonate and then “etc.,” which leaves room for interpretation without settling the question. How much an occasional chewable shifts amphetamine levels for any one person isn’t spelled out in the labeling.
The useful move: Note how often you reach for them. A roll in the desk drawer used once a month is a different story from four tablets every day with breakfast. That frequency is the detail your pharmacist will want.
Case 3: The bottle you shake (magnesium and aluminum hydroxide liquids)
The clue: “Aluminum hydroxide” and “magnesium hydroxide” together, often with simethicone. Mylanta and Maalox liquids are the common examples. Milk of magnesia is magnesium hydroxide alone and is usually sold as a laxative, though the label may list an antacid use too.
What it means: Same category as Case 2: they neutralize stomach acid, and the Evekeo labels don’t name them. Liquids are often taken repeatedly when reflux flares, so the total can add up quickly.
A side note from the same panel: Magnesium-containing products can loosen stools, and aluminum-containing ones can firm them up. If your stomach complaint is really stimulant-related queasiness rather than heartburn, an antacid may not be the right tool anyway. Our sibling guide on Evekeo and nausea walks through that distinction.
Case 4: The “acid reducer” box (famotidine, omeprazole and relatives)
The clue: The front says “acid reducer,” not “antacid.” The active ingredient will be either an H2 blocker (famotidine, cimetidine, nizatidine) or a proton pump inhibitor (omeprazole, esomeprazole, lansoprazole). Omeprazole products sometimes also contain sodium bicarbonate, which is worth spotting.
What it means: These products don’t neutralize acid already in your stomach. They tell the stomach to make less of it. MedlinePlus explains that H2 blockers reduce acid made by glands in the stomach lining and take roughly 30 to 90 minutes to start working, with effects lasting several hours. PPIs block acid production more strongly and are usually taken daily for a course. Either way, the stomach becomes less acidic for hours at a time, not just for a few minutes after a chewable.
What the Evekeo labels say: Nothing, specifically. Neither label mentions PPIs or H2 blockers. However, the MedlinePlus amphetamine drug information page, which covers Evekeo and Evekeo ODT among other brands, does list cimetidine, esomeprazole, and omeprazole among the medicines to mention to your doctor and pharmacist. If you’ve been started on a daily PPI by a gastroenterologist, or you’ve been taking one from the drugstore for weeks, that belongs on your medication list for the stimulant prescriber.
OTC acid reducer packages also set limits on how long to use them without seeing a doctor. Needing heartburn relief most days is worth discussing in its own right.
Case 5: The vitamin packet that fizzes (ascorbic acid plus bicarbonate)
The clue: This one is sneaky because it isn’t sold as a stomach medicine at all. Effervescent “immune support” tablets such as Airborne list vitamin C (as ascorbic acid) in the Supplement Facts panel, often 1,000 mg per tablet. Then, under the ingredients line, you’ll find sodium bicarbonate, potassium bicarbonate, and citric acid, which create the fizz.
What it means: The same glass holds ingredients from both sides of the Evekeo label. Ascorbic acid is named as an acidifying agent. Sodium bicarbonate is named as an alkalinizing agent. Which effect wins, and by how much, depends on the product’s formula and isn’t something the Evekeo labeling calculates for you. That uncertainty is exactly why these packets are worth asking about rather than guessing.
Related evidence: Fruit juices are listed on the Evekeo tablet label as gastrointestinal acidifying agents, and high-dose vitamin C tablets without bicarbonate sit firmly on the acidifying side. People sometimes wash a morning tablet down with orange juice out of habit. That’s a habit worth mentioning to your pharmacist.
Case 6: The prescription bottle (potassium citrate and other urinary alkalinizers)
The clue: This evidence isn’t on a store shelf. It’s on a pharmacy label from another prescriber. Mayo Clinic describes potassium citrate (brand Urocit-K) as a prescription extended-release tablet that makes urine less acidic. It’s used for certain kinds of kidney stones and renal tubular acidosis. Acetazolamide, sometimes prescribed for glaucoma or altitude sickness, and some thiazide diuretics for blood pressure also appear on the Evekeo tablet label as urinary alkalinizing agents.
What it means: These work on the kidney side. Less acidic urine means less amphetamine is flushed out, which the label says raises blood levels. Taken daily, their effect is more sustained than a one-off antacid’s.
The useful move: Make sure both prescribers know about both medicines. A urologist starting potassium citrate may not know about a stimulant prescribed by a psychiatrist or sleep specialist, and vice versa. Filling everything at one pharmacy helps the interaction checks catch it.
The evidence board: product type, ingredient, and what to ask
Use this table as a quick reference when you’re standing in the aisle. The “What the Evekeo label says” column reflects the tablet and ODT labels as posted on DailyMed in October 2026. Where a label is silent, the table says so.
| Product type | Active ingredient to look for | Acidifies or alkalinizes? | What the Evekeo label says | Question to ask |
|---|---|---|---|---|
| Effervescent antacid (Alka-Seltzer-type) | Sodium bicarbonate (often with citric acid; Original also has aspirin) | Alkalinizes the stomach | Named example of a GI alkalinizing agent; may increase absorption and blood levels | “Is this a product I should avoid or limit while on Evekeo?” |
| Baking soda used as a home remedy | Sodium bicarbonate | Alkalinizes the stomach | Same as above | “What should I use for heartburn instead?” |
| Chewable antacid (Tums, Rolaids) | Calcium carbonate; some add magnesium hydroxide | Neutralizes stomach acid (alkaline side) | Not named; tablet label says “sodium bicarbonate, etc.” | “I use these about X times a week. Does that matter with my dose?” |
| Liquid antacid (Mylanta, Maalox, milk of magnesia) | Aluminum hydroxide, magnesium hydroxide | Neutralizes stomach acid (alkaline side) | Not named | “Is occasional use OK, and is there a better option for me?” |
| H2 blocker acid reducer | Famotidine, cimetidine, nizatidine | Reduces acid production for hours | Not mentioned on either Evekeo label | “Should my stimulant prescriber know I take this?” |
| PPI acid reducer | Omeprazole, esomeprazole, lansoprazole (some with sodium bicarbonate) | Strongly reduces acid production | Not mentioned on either Evekeo label; MedlinePlus lists omeprazole and esomeprazole as medicines to report | “Could a daily PPI change how my Evekeo works?” |
| Effervescent vitamin C | Ascorbic acid plus sodium or potassium bicarbonate | Mixed: contains named ingredients from both sides | Ascorbic acid named as acidifying; sodium bicarbonate named as alkalinizing | “Is this packet a problem with my morning dose?” |
| Plain vitamin C or fruit juice | Ascorbic acid; citrus juices | Acidifies | Named GI acidifying agents; may lower absorption and efficacy | “Does what I drink with my tablet matter?” |
| Prescription urinary alkalinizer | Potassium citrate (Urocit-K), acetazolamide, some thiazides | Alkalinizes urine | Urinary alkalinizers decrease excretion and raise blood levels (acetazolamide and thiazides named) | “Do my two prescribers know about each other’s medicines?” |
| Prescription urinary acidifier | Ammonium chloride, sodium acid phosphate | Acidifies urine | Increase excretion; lower blood levels and efficacy | “Will this make my Evekeo less effective?” |
Our Dexedrine and antacids article covers the same chemistry for a dextroamphetamine-only medicine. Its label wording is close to Evekeo’s tablet label, but Dexedrine doesn’t come as an orally disintegrating tablet. That difference is the next part of the investigation.
Clues from the ODT itself
Evekeo ODT dissolves on the tongue, which changes the practical questions a little. The label’s administration steps are specific:
- Keep the tablet in its blister until just before the dose, and don’t store it loose for later.
- Open the blister with dry hands.
- The Evekeo ODT label says to push the tablet through the back of the foil-lined blister, then place the whole tablet on the tongue right away.
- Let it disintegrate in saliva without chewing or crushing. It can be moved between the tongue and the roof of the mouth until it breaks down.
- No liquid is needed, though the label also says it may be taken with or without food or liquid.
One small discrepancy deserves mention. The MedlinePlus amphetamine page, which covers several amphetamine ODT brands at once, tells readers to peel back the foil rather than push the tablet through. Packaging differs between brands, so follow the instructions that came with your specific product, and ask the pharmacist to show you if the blister seems hard to open without breaking the tablet.
What the ODT pharmacokinetic data shows
The ODT label reports that the median time to peak levels of d- and l-amphetamine was about 3.5 hours when taken without water and 3.0 hours with water. With food, median time to peak moved from 2.5 to 4.5 hours, while overall exposure and peak concentration weren’t affected. These figures come from controlled studies and don’t predict what any one person will feel, but they show the tablet behaves differently depending on what’s in the mouth and stomach at the time.
A label-reading lesson hidden in the ODT’s own ingredients
Evekeo ODT’s inactive ingredients include citric acid and malic acid, alongside mannitol and sucralose. These are formulation helpers in the approved product, and the label doesn’t treat them as an interaction concern. The lesson: an ingredient’s name alone doesn’t tell the story. Amount and purpose matter, which is why the active ingredient line and the label’s own wording count for more than a scan for scary-sounding chemicals.
The “what do I drink it with” question
Because Evekeo ODT doesn’t need water, some families get into the habit of giving it with whatever’s on the breakfast table: juice, a fizzy vitamin drink, or nothing at all. Given that fruit juice and ascorbic acid are named acidifiers on the Evekeo tablet label, and that the ODT label names ascorbic acid as an example acidifying agent, it’s sensible to ask the pharmacist whether the drink matters for your child, and then keep the routine consistent from day to day.
Building your case file before the next appointment
A detective hands a well-organized file to someone who can act on it. When the question is Evekeo and antacids, that’s your prescriber and pharmacist.
Photograph the back of every box
Snap a phone picture of the Drug Facts or Supplement Facts panel on each heartburn product, vitamin, or fizzy drink mix in the house. Store brands often copy the packaging but not always the formula.
Note frequency, not just presence
Jot down roughly how often each product gets used. “Tums, maybe twice a month” and “omeprazole every morning for six weeks” lead to different conversations. If you can, note whether the use tends to fall near the Evekeo dose.
List every prescriber
Include the urologist, the gastroenterologist, the primary care doctor who added a thiazide, and anyone who prescribed acetazolamide for a trip. Urinary alkalinizers are easy to miss because nobody thinks of them as stomach medicines.
Describe what you noticed, if anything
If you’ve ever felt that a dose hit harder, lasted longer, or seemed weaker on a day when you used a particular product, describe it plainly: the date, what you took, what you felt. Don’t experiment to test the theory. Stronger-than-usual stimulant effects can include a racing or pounding heartbeat, feeling jittery or anxious, trouble sleeping, or a raised blood pressure reading. Chest pain, fainting, severe agitation, or signs of a stroke such as sudden weakness or trouble speaking need emergency care right away, so call 911.
Ask what to use instead
The best outcome isn’t just “avoid that.” It’s a named plan for the next heartburn flare. Your pharmacist can suggest an option that fits your full medication list. Any spacing advice should come from them, because neither Evekeo label sets an interval.
A note on safe storage. Evekeo is a Schedule II stimulant with a high potential for misuse. While you’re gathering boxes from the medicine cabinet, it’s a good moment to make sure the stimulant itself is stored securely, out of reach of children and visitors, and that any unused tablets are disposed of properly. Your pharmacy can tell you about take-back options.
Evekeo and antacids: questions readers ask
Is baking soda for heartburn a problem with Evekeo?
Baking soda is sodium bicarbonate, the ingredient both Evekeo labels name as an alkalinizing agent that can raise amphetamine levels. It’s one of the clearer cases in this guide. Ask your pharmacist for a heartburn option that fits better with your prescription.
Does the Evekeo label say anything about omeprazole or other PPIs?
No. Neither the Evekeo tablet label nor the Evekeo ODT label mentions proton pump inhibitors. MedlinePlus’s amphetamine page, however, lists omeprazole and esomeprazole among the medicines to tell your doctor about. Silence on the label isn’t a green light, so make sure your stimulant prescriber knows if you take one regularly.
My Rolaids lists two antacids. Does the magnesium hydroxide change anything?
Both calcium carbonate and magnesium hydroxide neutralize stomach acid, so they belong to the same general category. Neither is named on the Evekeo labels, which mention sodium bicarbonate as the example. Tell your pharmacist how often you use the product. Frequency is usually the more useful detail than which of the two ingredients it contains.
Can an effervescent vitamin C packet weaken or strengthen Evekeo?
It contains ingredients from both sides of the label: ascorbic acid, which the label names as acidifying, and bicarbonate, which the label names as alkalinizing. The net effect for any particular product isn’t described in the Evekeo labeling. Bring the package to your pharmacist rather than guessing.
Does Evekeo ODT have to be taken with water?
No. The ODT label says no liquid is needed because the tablet dissolves in saliva. It also says the tablet may be taken with or without food or liquid. If you do give it with a drink, ask whether juice or a fizzy vitamin drink is a good choice, and keep the routine consistent.
I was just prescribed potassium citrate for kidney stones. Does my Evekeo prescriber need to know?
Yes. Potassium citrate makes urine less acidic, and the Evekeo tablet label says urinary alkalinizing agents decrease amphetamine excretion and raise blood levels. Let both prescribers know, and ideally fill both prescriptions at the same pharmacy so interaction checks can run.
Does the antacid caution apply if Evekeo was prescribed for narcolepsy or weight loss rather than ADHD?
Yes. The interaction comes from how the body absorbs and clears amphetamine, which is the same no matter why it was prescribed. The Evekeo tablet carries all three indications. Evekeo ODT is labeled only for ADHD in children and teens aged 6 to 17.
References
- DailyMed: Evekeo (amphetamine sulfate tablets, USP) CII, prescribing information and Medication Guide (Azurity Pharmaceuticals; revised 06/2025).
- DailyMed: Evekeo ODT (amphetamine sulfate) orally disintegrating tablets CII, prescribing information and Medication Guide (revised 04/2024).
- MedlinePlus: Amphetamine drug information (U.S. National Library of Medicine).
- MedlinePlus: H2 blockers (U.S. National Library of Medicine).
- Mayo Clinic: Potassium citrate (oral route).
Related reading on Mediclox: what to do about a missed morning dose of Evekeo and the full Mediclox health blog.
This article is for general information and isn’t a substitute for advice from your prescriber or pharmacist. Evekeo and Evekeo ODT are Schedule II controlled substances with a boxed warning for abuse, misuse, and addiction. Don’t start, stop, or change the dose of any medicine, including over-the-counter antacids and acid reducers, without talking to the professional who manages your care. If you have chest pain, fainting, or other signs of a medical emergency, call 911.