Quick answer: The most common hydrocodone side effects are drowsiness, lightheadedness, dizziness, nausea, constipation and itching. Most fade within a few days as your body adjusts. The serious ones are slowed breathing, especially when hydrocodone is combined with alcohol or benzodiazepines, and liver damage from too much acetaminophen in combination products like Norco and Vicodin. Physical dependence can develop within a few weeks of daily use.
Most people who are handed a bottle of hydrocodone after surgery or a dental procedure get through it with a few groggy, queasy days and nothing worse. But “a few side effects” covers a wide range, from itchy skin that is annoying and harmless to slowed breathing that is not. This guide sorts hydrocodone’s side effects into what is common, what is serious, what changes with your dose, age and sex, and when a side effect is actually a reason to call someone.
What hydrocodone is
Hydrocodone is a prescription opioid, in the same family as oxycodone, morphine and codeine. It is semi-synthetic, made in a lab from codeine, and it works by attaching to mu-opioid receptors in the brain and spinal cord to turn down pain signals. For years it was the most prescribed opioid in the United States. Since October 2014 it has been a Schedule II controlled substance, the most tightly regulated category for a drug that can still be prescribed.
Nearly every hydrocodone prescription is a combination tablet with acetaminophen (the drug in Tylenol). You will see it as Norco, Lortab, the now-discontinued brand Vicodin, or generic “hydrocodone/acetaminophen” followed by two numbers, most often 5-325, 7.5-325 or 10-325. The first number is milligrams of hydrocodone; the second is milligrams of acetaminophen. That second number matters more than most people realize, and we come back to it below. Hydrocodone is also sold on its own as an extended-release tablet (Hysingla ER, Zohydro ER) for around-the-clock pain.
Common side effects and what helps
The prescribing information lists lightheadedness, dizziness, sedation, nausea and vomiting as the most frequently reported reactions. Constipation and itching are close behind. Here is what to expect from each and what usually helps.
| Side effect | How common | What usually helps |
|---|---|---|
| Drowsiness, sedation | Very common, strongest in the first few days | No driving until you know your response; avoid alcohol and other sedatives; take the last dose earlier in the evening. Full guide to hydrocodone and sleepiness. |
| Lightheadedness, dizziness | Very common | Stand up slowly; sit before you feel faint; stay hydrated. Worse in older adults and at higher doses. |
| Nausea, vomiting | Common, usually eases within a week | Take with food; small frequent meals; lying still for 30 minutes after a dose. Ask about an anti-nausea medication if it does not settle. |
| Constipation | Common, and it does not go away with time | Start a stool softener or gentle laxative the same day you start hydrocodone, not after the problem shows up. Fluids and fiber help but are rarely enough alone. |
| Itching | Common, especially face, neck and chest | Cool compresses, an over-the-counter antihistamine (which also adds drowsiness), a lower dose or a different opioid if it persists. See the section below. |
| Dry mouth | Common | Sips of water, sugar-free gum or lozenges. Brush and floss more than usual; dry mouth raises cavity risk over weeks. |
| Headache, sweating, mood changes, trouble urinating | Less common | Usually mild. Tell your prescriber if any of them are more than a nuisance. |
Why hydrocodone makes you itch
This is the single most searched hydrocodone side effect after drowsiness, and most articles give it one line. Itching on hydrocodone is usually not an allergy. Opioids trigger itch in two ways at once: they cause skin cells called mast cells to release histamine, which is the same chemical behind a mosquito bite, and they act directly on itch-signaling pathways in the spinal cord. That second route is why antihistamines like Benadryl help some people only partway; they address the histamine but not the nerve signal.
Typical opioid itch shows up within an hour or two of a dose, concentrates on the face, neck and upper chest, and comes without a rash or with only mild flushing. It often fades over the first several days. A cool shower, unscented moisturizer, and keeping your fingernails away from it are the low-tech answers. If it is bad enough to interfere with sleep, ask your prescriber about a lower dose or switching to a different opioid, since some people itch far less on one than another.
A true allergic reaction looks different, and it is an emergency: hives spreading across the body, swelling of the lips, tongue or throat, wheezing or trouble breathing, or a fast heartbeat. If any of that happens, stop the medication and call 911.
Serious side effects
These are less common, but they are the reason hydrocodone is a controlled substance and the reason the label carries the FDA’s strongest warnings.
Slowed or stopped breathing. Opioids suppress the brainstem’s drive to breathe. The risk is highest when you first start, when the dose goes up, in older adults and people with sleep apnea, COPD or asthma, and above all when hydrocodone is combined with alcohol, benzodiazepines (Xanax, Klonopin, Ativan, Valium), sleep medications, muscle relaxers or gabapentin. In 2016 the FDA added a boxed warning to every opioid and every benzodiazepine about combining them, because the combination causes extreme sedation, respiratory depression, coma and death. Slowed breathing is also what an overdose is; the signs are at the end of this article.
Severe low blood pressure. Hydrocodone can drop blood pressure enough to cause fainting, particularly when standing up, in people who are dehydrated, or alongside blood pressure medications.
Adrenal insufficiency. Opioids can suppress the adrenal glands, usually after a month or more of use. The symptoms are vague, which is the problem: nausea, vomiting, loss of appetite, fatigue, weakness, dizziness and low blood pressure. If those show up weeks into treatment rather than in the first days, mention it to your prescriber; it is treatable but easy to miss.
Serotonin syndrome. Combining hydrocodone with antidepressants (SSRIs, SNRIs, tricyclics, MAOIs) or triptan migraine medications can, uncommonly, cause agitation, rapid heartbeat, high temperature, muscle twitching and confusion. Make sure whoever prescribes the hydrocodone knows about every antidepressant you take.
Hearing loss. A rare one that surprises people: long-term, high-dose use of hydrocodone/acetaminophen has been linked to tinnitus and sensorineural hearing loss, and it is not always reversible. New ringing in the ears or muffled hearing on hydrocodone is a reason to call, not wait.
Liver damage from acetaminophen. Serious enough to get its own section.
The acetaminophen problem
The boxed warning on Norco and every other hydrocodone/acetaminophen product is not primarily about the opioid. It is about acetaminophen, which causes acute liver failure at doses that are not far above the therapeutic range. The label caps total acetaminophen at 4,000 mg a day from all sources, and the Norco label caps the tablets themselves at six a day.
The trap is the “all sources” part. Tylenol, Excedrin, NyQuil, DayQuil, most “PM” pain relievers and many cold and flu products contain acetaminophen. Someone taking six Norco 10-325 tablets (1,950 mg of acetaminophen) who adds two Extra Strength Tylenol (1,000 mg) for a headache and a nighttime cold medicine is at or over the limit without ever taking more hydrocodone than prescribed. Alcohol lowers the threshold further. Read the label of anything else you take, and treat “acetaminophen” and “APAP” as the same word.
Side effects by dose
The opioid side effects scale with the first number on the label, so a 10-325 tablet will generally cause about twice the drowsiness, dizziness, nausea and constipation of a 5-325, while the acetaminophen exposure per tablet is the same. People searching “hydrocodone/acetaminophen 5-325 side effects” are usually asking whether the lowest common dose is enough to cause trouble. It is: 5 mg is enough to make most opioid-naive adults drowsy and to cause constipation and itching. The difference at higher doses is mostly in degree and in breathing risk, which climbs steeply when 10 mg tablets are taken more often than prescribed or combined with other sedatives.
Side effects in women, men and older adults
Women report nausea and vomiting on opioids somewhat more often than men, and hydrocodone can disrupt the menstrual cycle with longer-term use because opioids lower sex hormone levels. Missed or irregular periods after weeks on hydrocodone are worth mentioning to a provider. Hydrocodone should be avoided in pregnancy when possible because regular use can cause neonatal opioid withdrawal syndrome in the baby; if you are pregnant or could become pregnant, that conversation belongs at the first appointment, not the last.
Men on opioids for more than a few weeks can develop low testosterone. The FDA added this to every opioid label in 2016. It shows up as low libido, erectile dysfunction, fatigue and low mood, and it is often blamed on everything except the medication. It usually reverses when the opioid stops.
Older adults feel every hydrocodone side effect more, because the drug clears more slowly and the brain is more sensitive to it. Dizziness and sedation translate directly into falls and fractures; constipation is more stubborn; confusion is more likely. The American Geriatrics Society’s Beers Criteria, the standard list of medications that carry extra risk after 65, flags hydrocodone/acetaminophen, and prescribers are advised to start lower and go slower. If you are caring for an older parent on hydrocodone, the two things to watch are unsteadiness on their feet and any new confusion.
How long side effects last
For a single dose, most side effects track the medication: they begin within 30 minutes to an hour, peak around one to two hours, and fade over four to six hours. Across a course of treatment, drowsiness, nausea, dizziness and itching usually ease within the first several days as tolerance develops. Constipation does not; the gut never adjusts, so it needs to be managed for as long as you take the drug. Dry mouth also tends to persist. If a side effect that should have faded is still strong after a week on a steady dose, the dose may be higher than you need.
Side effects of stopping
The label is direct about this: physical dependence can develop after several weeks of regular use, and stopping suddenly then causes withdrawal. Hydrocodone withdrawal feels like a bad flu with anxiety attached: aches, sweating, chills, runny nose, stomach cramps, diarrhea, restlessness, insomnia and intense cravings, starting within about 12 hours of the last dose and peaking around day two or three. It is rarely dangerous on its own, but it is miserable enough that many people go back to the pills just to make it stop, which is how a short prescription turns into a long one.
Dependence is a normal biological response and is not the same thing as addiction. But it is the point where stopping gets hard without help. If you have been on hydrocodone for more than a few weeks, ask your prescriber about tapering rather than stopping cold. If you are already past that point, our guide to getting through opioid withdrawal safely covers what a medically supported taper looks like.
Signs of overdose
Call 911 if someone who has taken hydrocodone cannot be woken or drifts back off mid-sentence, is breathing slowly or shallowly with long pauses or a gurgling sound, has pinpoint pupils, or has blue or gray lips, fingertips or skin. Give naloxone (Narcan) if you have it and stay with the person. Naloxone is available at any Massachusetts pharmacy without a prescription, and the state’s Good Samaritan law protects the person who calls for help. If anyone in your household takes hydrocodone regularly, it is reasonable to keep naloxone in the house.
When side effects are a sign of something bigger
Most side effects on this list are the body adjusting to a medication it will be done with in a week or two. A few are signs that the relationship with the medication has changed: needing more for the same relief, taking it for the calm rather than the pain, feeling sick when a dose is late, running out early, or spending real energy thinking about the next refill. None of that means someone is weak or did something wrong. It means the medication is now doing something it was never prescribed to do, and it is far easier to address at this stage than later.
At Rockland Recovery in Braintree, we work with people at every point on that line, from someone who is worried about a prescription that has run long to someone whose use has moved well past it. That includes medically supervised detox, so withdrawal is managed rather than endured, and medication-assisted treatment with buprenorphine (Suboxone) or naltrexone (Vivitrol), which quiets cravings and withdrawal without the high. Most commercial insurance and MassHealth cover it. Call 855-732-4842. The call is confidential and you do not have to decide anything on it.
For a comparison with the other opioid you are most likely to be prescribed, see oxycodone vs. hydrocodone.
Frequently asked questions
Does hydrocodone make you itch?
Yes, and it is one of its most common side effects. Opioids release histamine in the skin and act on itch pathways in the spinal cord, so the itching is usually a drug effect rather than an allergy. It typically affects the face, neck and chest and fades over the first several days. Spreading hives, facial swelling or trouble breathing are different and need emergency care.
What are the side effects of hydrocodone/acetaminophen 5-325?
The same as any hydrocodone dose, mainly drowsiness, dizziness, nausea, constipation and itching, at the milder end of the range. Five milligrams is still enough to cause noticeable drowsiness in most people who have not taken opioids before. Each tablet also carries 325 mg of acetaminophen toward the 4,000 mg daily limit.
How long do hydrocodone side effects last?
Per dose, four to six hours. Over a course of treatment, drowsiness, nausea and itching usually ease within several days. Constipation and dry mouth persist for as long as you take it and need to be managed rather than waited out.
What are hydrocodone side effects in women?
The common effects are the same, though women tend to report nausea somewhat more often. With longer use, opioids can lower sex hormone levels and disrupt periods. Hydrocodone in pregnancy can cause withdrawal symptoms in the newborn, so pregnancy or the possibility of it should be discussed before starting.
What are hydrocodone side effects in the elderly?
Older adults clear hydrocodone more slowly and feel it more. The biggest risks are falls from dizziness and sedation, new confusion, stubborn constipation, and slowed breathing. The Beers Criteria flag hydrocodone/acetaminophen as higher-risk after 65, and doses are usually started lower.
Does hydrocodone cause dry mouth?
Yes, and unlike drowsiness it tends not to fade. Water, sugar-free gum and extra attention to brushing help, since a dry mouth for weeks raises the risk of cavities.
Is hydrocodone an opioid?
Yes. Hydrocodone is a semi-synthetic opioid made from codeine, in the same family as oxycodone and morphine. It has been a Schedule II controlled substance since 2014.
This article is for general education and is not medical advice. Hydrocodone should only be taken as prescribed, and questions about side effects, dose or stopping should go to a licensed provider who knows your history. If you think someone is overdosing, call 911.
Sources
- DailyMed (National Library of Medicine). Norco (hydrocodone bitartrate and acetaminophen) prescribing information. Boxed warning, most common adverse reactions, acetaminophen limit, dosing.
- MedlinePlus (National Library of Medicine). Hydrocodone Combination Products.
- StatPearls (NCBI Bookshelf). Hydrocodone. Adverse effects by system, including pruritus, adrenal insufficiency, hearing loss; geriatric considerations and Beers Criteria.
- U.S. Food and Drug Administration. FDA warns about several safety issues with opioid pain medicines; requires label changes (March 2016: serotonin syndrome, adrenal insufficiency, decreased sex hormone levels).
- U.S. Food and Drug Administration. New Safety Measures Announced for Opioid Analgesics, Prescription Opioid Cough Products, and Benzodiazepines (boxed warning on combined use).
- Drug Enforcement Administration. Rescheduling of Hydrocodone Combination Products From Schedule III to Schedule II.
- National Institute on Drug Abuse. Opioids.