Lortab side effects and when to call a doctor

Lortab side effects at a glance: green, yellow, red

Think of this section as a sorting tray. Find the symptom you have, see which color it lands in, and act on that color.

Common Lortab side effects and what helps

Most hydrocodone acetaminophen side effects come from the hydrocodone part. Hydrocodone attaches to opioid receptors, which sit in the brain and spinal cord but also in the gut, the skin, and the breathing center. That spread explains why one pill can ease pain and also slow your bowels or make your nose itch.

Effect	Why it happens	What usually helps
Constipation	Opioid receptors in the gut slow the muscle waves that move stool along and dry it out	Fluids, fiber if you can tolerate it, gentle movement, and a laxative plan your pharmacist suggests from day one
Drowsiness	Hydrocodone dampens activity in the brain’s alertness centers	Skip driving and ladders, avoid alcohol and sleep aids, and let others know you’re on an opioid
Nausea or vomiting	It stimulates the brain’s “vomit trigger zone” and slows stomach emptying	Take with a small snack, rise slowly, ask about an anti-nausea medicine if it lasts
Itching	Opioids can release histamine from cells in the skin	Cool showers and fragrance-free lotion; ask before using an antihistamine, since many add drowsiness
Dizziness on standing	Blood vessels relax and blood pressure can dip	Sit on the edge of the bed for a minute before standing; hold a rail
Dry mouth	Less saliva production	Sips of water, sugar-free gum, regular brushing
Trouble urinating	The bladder muscle relaxes and the outlet tightens	Report it, especially if you have an enlarged prostate
Sweating or flushing	Effects on temperature control and skin blood flow	Light layers; mention it if it is heavy or new

Lortab constipation deserves a plan, not a wait-and-see

Here is the one side effect that rarely goes away on its own. Your body usually gets used to the sleepiness and nausea within days. The gut, though, keeps reacting for as long as you take the drug.

Many prescribers suggest starting a stool softener or a gentle stimulant laxative at the same time as the opioid, rather than after a problem builds up. Fiber alone can backfire if you are not drinking much water. For more detail, see our guide on how hydrocodone causes constipation and how to prevent it, plus our broader list of what helps with constipation.

Lortab itching: allergy or not?

A warm, itchy feeling on the face, neck, or chest without a raised rash is usually a histamine effect, not a true allergy. It tends to ease after a few doses. Hives, swelling, or breathing trouble are different, and those belong in the red group above.

Drowsiness and your daily routine

Sleepiness peaks in the first few days and after any dose increase. During that window, it is safest not to drive, use power tools, or care for small children alone. Our article on driving while taking hydrocodone covers the legal and safety side in more depth.

Nausea in the first few days

Queasiness is most common with the first handful of doses and often settles within a few days. Lying still for a short while after a dose can help, since movement makes opioid nausea worse for some people. An empty stomach tends to make it worse too, so a few crackers or a piece of toast before the tablet is worth trying.

If vomiting means you can’t keep a dose down, don’t simply take another tablet to make up for it. Call your pharmacist or prescriber for advice, because you can’t know how much of the first dose was absorbed.

Is it the medicine, or the injury?

After surgery or an accident, some symptoms come from the recovery itself. Anesthesia, lying in bed, dehydration, and stress can all cause nausea, fatigue, and sluggish bowels. That overlap is one reason a quick call to your care team is better than guessing. They know which effects are expected after your procedure and which point to the pills.

Serious side effects of Lortab

The prescribing information for hydrocodone and acetaminophen tablets, available on DailyMed, carries a boxed warning. That is the FDA’s strongest label alert. It covers addiction and misuse, life-threatening breathing problems, accidental swallowing by someone else, withdrawal in newborns after use in pregnancy, drug interactions, liver damage, and danger when mixed with benzodiazepines or other sedatives.

The serious Lortab side effects below are uncommon when the medicine is used as directed for a short time. They are still worth knowing by sight, because early action changes outcomes.

Slowed or shallow breathing

This is the most dangerous effect of any opioid. Hydrocodone quiets the brainstem area that tells you to breathe, especially at higher doses, right after a dose increase, or when combined with other sedating substances.

Warning signs include breathing that is slow, shallow, or irregular, snoring that sounds like gurgling, and lips that turn blue or gray. Someone with these signs needs 911. If naloxone is on hand, use it first.

Extreme sleepiness or confusion

Feeling a bit drowsy is expected. Being impossible to wake, falling asleep mid-sentence, or acting confused is not. In older adults, confusion can be the first sign that a dose is too strong for their body. Treat it as urgent.

Liver injury from acetaminophen

Every current Lortab-type tablet contains 325 mg of acetaminophen. The FDA’s daily ceiling for adults is 4,000 mg from all sources combined, and many people do best well under that. Most serious liver injury cases have involved going over 4,000 mg a day, often by taking more than one acetaminophen product at once.

Early liver damage can feel like nothing at all, or like a stomach bug: nausea, loss of appetite, and tiredness. Later signs include pain under the right ribs, dark urine, and yellow skin or eyes. If you think you have taken too much acetaminophen, call Poison Control at 1-800-222-1222 or use poison.org, even if you feel fine. Our Lortab acetaminophen limit guide walks through the daily math.

Serious skin reactions

Acetaminophen can, rarely, trigger severe skin reactions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and acute generalized exanthematous pustulosis. The FDA added a warning about these in 2013. They can start with flu-like feelings, then a red or purple rash that blisters or peels. Stop taking the medicine and get emergency care if this happens.

Serotonin syndrome

Opioids, including hydrocodone, can contribute to serotonin syndrome when combined with drugs that raise serotonin. Those include many antidepressants (SSRIs, SNRIs, tricyclics), triptans for migraine, some anti-nausea drugs, and MAO inhibitors. Signs include agitation, fast heartbeat, fever, heavy sweating, shivering, muscle twitching or stiffness, and diarrhea. This is an emergency.

Adrenal insufficiency

Opioid labels warn that using these drugs, usually for more than a month, can sometimes reduce the adrenal glands’ output of cortisol. Symptoms are vague: nausea, vomiting, poor appetite, deep fatigue, weakness, dizziness, and low blood pressure. A blood test can check, and treatment is available.

Low blood pressure and fainting

Hydrocodone can lower blood pressure, especially in people who are dehydrated, already on blood pressure medicine, or recovering from surgery. A brief head rush is common. Fainting or a fall is not, and it should be reported the same day.

Lortab allergic reaction

True allergy to hydrocodone or acetaminophen is uncommon but possible. Hives, swelling of the lips, tongue, or throat, wheezing, and trouble swallowing can point to anaphylaxis. Use an epinephrine auto-injector if you have one for a known allergy and call 911.

Long-term Lortab use: effects that build slowly

Short courses after surgery or an injury rarely run into these issues. They tend to show up after weeks or months of daily use. If you have been taking hydrocodone for a long stretch, it helps to know what to watch for.

Tolerance

Over time, the same dose may ease pain less than it used to. That is your nervous system adjusting, not a sign you are doing something wrong. It does mean “just take another one” is not a safe answer. Talk with your prescriber about the plan, including non-opioid options.

The CDC’s 2022 opioid prescribing guideline encourages prescribers to check in regularly on whether an opioid is still helping more than it is hurting. Those visits are a good time to bring up any side effect that has crept in over months.

Physical dependence

After regular use, your body comes to expect the drug. Stopping suddenly can cause withdrawal: aches, yawning, runny nose, sweating, diarrhea, anxiety, and poor sleep. Dependence is not the same as addiction, though both can occur. The FDA has warned that suddenly stopping opioids in people who are dependent has led to serious harm, including uncontrolled pain and suicide. A gradual plan works better; see our guide to Lortab withdrawal and tapering.

Addiction (opioid use disorder)

Some people develop cravings, lose control over how much they take, or keep using despite harm. This is a medical condition with effective treatment, not a moral failure. Our page on hydrocodone addiction explains the signs and the options.

Opioid-induced hyperalgesia

Here is a strange twist: in some people, opioids can make the nervous system more sensitive to pain. The pain may spread to new areas or feel worse even as the dose climbs. It differs from tolerance because more medicine makes it worse, not better. Updated opioid labels now describe this effect. If your pain is expanding instead of easing, tell your prescriber.

Hormone changes

Long-term opioid use can lower sex hormones. In men, that can mean low testosterone, reduced sex drive, erectile problems, and fatigue. In women, it can mean irregular periods. Labels list this as a possible effect of chronic use, and blood tests can check levels.

Sleep-disordered breathing

Opioids can cause central sleep apnea, where the brain briefly stops sending the signal to breathe during sleep. Risk rises with higher doses. Loud snoring, gasping, or morning headaches are worth mentioning, particularly if you already have obstructive sleep apnea.

Who is more vulnerable to Lortab side effects

The same tablet can affect two people very differently. Certain groups tend to feel side effects more strongly or face higher risk of the serious ones.

• Older adults. Slower kidney and liver clearance means the drug lingers. Confusion, falls, and constipation are more common. Our guide to hydrocodone side effects in older adults covers Lortab side effects in elderly family members in more depth.
• People with lung conditions. COPD, severe asthma, and sleep apnea leave less breathing reserve.
• People with liver disease or heavy drinking. Both raise the risk of acetaminophen liver injury.
• People with kidney disease. Drug byproducts may build up.
• Anyone new to opioids. Sleepiness and breathing effects are stronger before tolerance develops.
• People taking other sedating medicines. More on that below.
• Pregnant people. Regular use late in pregnancy can lead to neonatal opioid withdrawal syndrome in the baby.
• People with low body weight or poor nutrition. Lower glutathione stores make the liver more fragile against acetaminophen.

Interactions that turn mild side effects into dangerous ones

On its own, a prescribed dose of hydrocodone is usually tolerated well. Add a second sedating substance, and the effects can stack rather than simply add up. Several drug interactions can also raise hydrocodone levels in the blood.

Combined with	What can happen
Benzodiazepines (alprazolam, lorazepam, diazepam)	Deep sedation, slowed breathing, coma, death. This combination carries its own boxed warning.
Alcohol	Stacked sedation plus added liver strain from acetaminophen
Gabapentin or pregabalin	Increased drowsiness and breathing risk
Sleep aids, muscle relaxers, sedating antihistamines	More sleepiness and slower reaction times
CYP3A4 inhibitors (clarithromycin, azole antifungals, some HIV drugs, grapefruit)	Hydrocodone builds up in the blood, raising overdose risk
CYP3A4 inducers (rifampin, carbamazepine, phenytoin), especially when stopped	Starting them can weaken pain relief; stopping them can let hydrocodone levels climb
Serotonergic drugs (SSRIs, SNRIs, triptans)	Possible serotonin syndrome
Other acetaminophen products	Hidden double-dosing and liver injury

If you also take a nerve-pain medicine, read our article on hydrocodone and gabapentin. Drinking is covered in detail in Lortab and alcohol. A full list of your medicines, including over-the-counter and herbal products, lets your pharmacist screen for these problems.

Keep a side-effect diary

Memory gets fuzzy when you are in pain and a little sedated. A short daily log gives your prescriber real information instead of guesses, and it often reveals patterns, like nausea that only shows up when you skip breakfast.

Jot down these items once or twice a day, in a phone note or on paper:

1. The time of each dose and the strength on the bottle.
2. Your pain level from 0 to 10 before the dose and about an hour after.
3. Any side effect you notice and how strong it felt (mild, moderate, severe).
4. Bowel movements, so you can spot a three-day gap early.
5. Other medicines taken that day, including cold remedies and sleep aids.
6. Any alcohol, even one drink.
7. How you slept, and whether anyone noticed loud snoring or pauses.
8. Questions you want to ask at the next visit.

Bring the diary to follow-up appointments. If you need to call about a yellow-zone symptom, having the details in front of you makes the call faster and more useful.

Frequently asked questions

What are the most common Lortab side effects?

The most common are drowsiness, constipation, nausea, lightheadedness, and itching. Drowsiness and nausea often ease within a few days. Constipation usually lasts as long as you take the medicine, so plan for it early.

How long do Lortab side effects last?

Hydrocodone has a half-life of about 4 hours, so effects from a single dose usually fade within several hours. Some effects, like sleepiness, lessen over the first few days of regular use as your body adjusts. Constipation and long-term effects can persist until the medicine is stopped.

Is itching from Lortab an allergic reaction?

Usually not. Mild itching or flushing without a raised rash is a common histamine-related effect of opioids. Hives, facial swelling, or trouble breathing, however, can signal a true allergic reaction and need emergency care.

Can Lortab damage your liver?

The acetaminophen in Lortab can harm the liver if you take more than the daily limit or combine it with other acetaminophen products. Heavy drinking, liver disease, and fasting raise the risk. Staying within your prescribed dose and checking other labels for acetaminophen greatly lowers it.

When should I call a doctor about Lortab side effects?

Call the same day for constipation lasting three days or more, vomiting that stops you from keeping fluids down, confusion, trouble urinating, or pain that is getting worse. Call 911 for slow or shallow breathing, if someone can’t be woken, for swelling of the face or throat, or for a blistering rash.

Are Lortab side effects worse in older adults?

They often are. Older adults clear the drug more slowly, so confusion, dizziness, falls, and constipation are more common. Prescribers usually start lower and watch more closely, and families should know the warning signs.

Can I take something for nausea while on Lortab?

Possibly, but ask your pharmacist first. Some anti-nausea and antihistamine medicines add drowsiness, and a few raise serotonin levels. Taking your dose with a light snack and getting up slowly often helps on its own.

Do side effects mean I’m addicted?

No. Side effects like constipation or sleepiness are expected reactions to the drug and say nothing about addiction. Addiction involves cravings, loss of control, and continued use despite harm, and it deserves a frank talk with your prescriber if you notice those signs.

Takeaway: know your colors

Most Lortab side effects are green-zone problems: sleepiness, nausea, itching, and especially constipation, which deserves a plan from the first dose. Yellow-zone symptoms like confusion, vomiting, or worsening pain call for a same-day phone call. Red-zone signs, above all slow breathing or someone who won’t wake up, mean naloxone and 911.

Your risk drops a lot when you stay within the acetaminophen limit, avoid alcohol and other sedatives, keep a simple diary, and tell your prescriber about every other medicine you use.

This article is for education and is not medical advice. Do not start, stop, or change any medicine without talking to your prescriber. Hydrocodone and acetaminophen is a controlled substance and should be used only with a valid prescription, exactly as directed. If you suspect an overdose, call 911 right away. For a possible acetaminophen overdose, call Poison Control at 1-800-222-1222. If you or someone you love is struggling with opioid use, the SAMHSA National Helpline is free, confidential, and open 24/7 at 1-800-662-4357.

Sources

• DailyMed: Hydrocodone bitartrate and acetaminophen tablets, prescribing information
• Drugs.com: Lortab
• FDA (2019): Harm reported from sudden discontinuation of opioid pain medicines
• FDA (2025): Opioid analgesic labeling safety communication
• CDC: Clinical Practice Guideline for Prescribing Opioids for Pain, 2022
• Poison Control (poison.org)
• SAMHSA National Helpline