Hydromorphone belongs to the family of medications known as opioid analgesics (narcotic pain relievers). It is used to treat moderate-to-severe pain, including pain after surgery. Hydromorphone works on the brain to increase the ability to tolerate pain. Hydromorphone begins to work within 30 minutes for oral (by mouth) forms.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The usual adult starting dose of hydromorphone taken by mouth is 2 mg to 4 mg every 4 to 6 hours as required. Hydromorphone should not be used for more than 7 days without first checking with your doctor.

Swallow the tablets whole with fluids. Cutting, breaking, chewing, crushing, or dissolving hydromorphone tablets can result in dangerous adverse events, including death.

Use an oral syringe to measure each dose of the liquid, as it gives a more accurate measurement than household teaspoons. The oral liquid may be diluted in fruit juice or another beverage if desired.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

After a certain dose of hydromorphone has been taken for a period of time, the body often gets used to it and a higher dose of hydromorphone is needed to relieve the pain. Generally, your doctor will try to find the dose of hydromorphone that will give you acceptable pain relief without an unacceptable level of side effects. This helps to reduce the side effects of the medication and allows for the dose to be adjusted upwards if needed. Always check with your doctor if you feel your medication isn't working well anymore.

Over time, this medication may produce tolerance and physical dependence as your body becomes used to the drug. Tolerance occurs when a dose that used to provide acceptable pain relief is no longer effective, and higher doses are required to achieve the same level of pain relief. Physical dependence is a state where the body will go into withdrawal if the medication is stopped suddenly. If you have been taking morphine on a regular basis for a long period of time, talk to your doctor before stopping the drug, as withdrawal effects can occur.

Tolerance and physical dependence are not the same as addiction. Addiction is defined as a psychological need to use the medication for reasons other than pain relief. Although people may become addicted to this medication, it is most common for people who have had addictions to other substances in the past.

It is important that this medication be taken exactly as prescribed by your doctor. If you miss a dose, take or use it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take or use a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature and keep it out of the reach of children.

Do not take hydromorphone if you:

• are allergic to hydromorphone or any ingredients of the medication
• are allergic to other opioid (narcotic) pain medications (e.g., morphine, codeine, oxycodone)
• are experiencing acute alcoholism or delirium tremens
• are taking or have taken a monoamine oxidase inhibitor (MAOI; tranylcypromine, rasagiline, selegiline, moclobemide) in the last 14 days
• have acute asthma or other obstructive airway disease
• have acute respiratory depression (slowed breathing)
• have a head injury or increased intracranial pressure (increased pressure inside the head)
• have severe central nervous system (CNS) depression (e.g., slowed nervous system)
• have suspected abdominal conditions which may require surgery (i.e., appendicitis, pancreatitis)
• have a blockage of the gastrointestinal tract, particularly paralytic ileus
• have pain that is mild or intermittent and can be treated with other pain medications
• have a seizure disorder
• are breast-feeding, pregnant, or in labour

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• confusion
• constipation
• decreased ability or interest in sexual activity
• decreased appetite
• decreased coordination
• dizziness, lightheadedness, or feeling faint
• drowsiness
• dry mouth
• headache
• nausea
• nightmares or unusual dreams
• trouble sleeping
• vomiting
• weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• anxiety
• blurred or double vision or other changes in vision
• fast, slow, or pounding heartbeat
• increased sweating
• itching
• shortness of breath, wheezing, or troubled breathing
• symptoms of a bowel blockage (e.g., abdominal pain, severe constipation, nausea)
• withdrawal symptoms (e.g., nausea, vomiting, diarrhea, anxiety, shivering, cold and clammy skin, body aches, loss of appetite, sweating)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• seizures
• signs of a severe allergic reaction (hives; difficulty breathing; swelling of the face, throat, or tongue)
• symptoms of overdose (e.g., hallucinations, confusion, inability to walk normally, slow or weak breathing, "pinpoint" pupils of the eyes, extreme sleepiness, dizziness, floppy muscles, cold and clammy skin)
• symptoms of serotonin syndrome (e.g., agitation or restlessness, loss of muscle control, muscle twitching, tremor, diarrhea)
• slow or troubled breathing

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take this medication.

Adrenal gland problems: Adrenal glands produce chemical messengers that are responsible for the normal function of the body's organs, including how your body responds to injury or stress. On rare occasions, particularly if it is taken for longer than a month, hydromorphone may cause your adrenal gland to function improperly. Your doctor may monitor your adrenal gland condition especially if you have experienced stress such as surgery, injury, or severe infection.

Alcohol and other medications that cause drowsiness:  People taking this medication should not combine it with alcohol, and avoid combining it with other medications that cause drowsiness, such as antidepressants, sleeping pills or anxiety medications. Doing so can cause additive drowsiness and reduced breathing, as well as other side effects, which can be dangerous and possibly life-threatening.

Abdominal (stomach) conditions: Like other narcotic medications, hydromorphone may make the diagnosis of abdominal conditions more difficult or it may worsen these conditions. If you have a history of abdominal problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Accidental use: Accidental ingestion or use of as little as one dose of hydromorphone by someone for whom it has not been prescribed can lead to a fatal overdose. Children are especially at risk. Keep this medication out of sight and reach of children.

Constipation: Constipation happens frequently while taking opioid (narcotic) pain relievers on a regular basis. Ask your doctor or pharmacist for advice on how to manage constipation.

Dependence and withdrawal: As with other opioid medications (narcotics), this medication may become habit-forming if taken for long periods of time. Misuse of hydromorphone usually is not a problem when it is used appropriately for pain relief. Withdrawal symptoms (e.g., body aches, diarrhea, nausea, nervousness, restlessness, runny nose, sneezing, goose bumps, shaking, shivering, nausea, stomach cramps, fast heart rate, fever, sweating) may occur if hydromorphone is stopped suddenly. Reducing the dose gradually under medical supervision can help prevent or decrease these withdrawal symptoms when this medication is no longer required for pain control.

Difficulty breathing: Hydromorphone can cause serious breathing problems. If you experience slowed breathing or difficulty breathing, seek immediate medical attention. People are more at risk for experiencing this if they have lung problems or a head injury or are taking other medications that can slow breathing. Make sure you follow the instructions on how to properly use this medication. If you have any questions, contact your doctor or pharmacist. If you have a chronic lung condition (e.g., bronchitis, emphysema, asthma, sleep apnea), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Drowsiness/reduced alertness: Hydromorphone may reduce the mental or physical abilities required for the performance of potentially hazardous tasks such as driving a car or operating machinery. Do not drive or operate dangerous machinery while using this medication unless you have determined that the medication does not affect your ability to do so.

Head injury: Hydromorphone can cause increased pressure inside the head. If you have experienced a head injury or other condition which increases the pressure inside your head, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney function: Decreased kidney function or kidney disease may cause this medication to build up in the body, causing side effects. If you have reduced kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. If you have reduced liver function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Low blood pressure: Hydromorphone can make low blood pressure worse or cause low blood pressure, which may be severe. If you experience severe dizziness, especially when standing from a lying or sitting position, contact your doctor.

Other medical conditions: Hydromorphone may cause increased symptoms or reduce the symptoms of worsening illness for people with the following conditions:

• Addison's disease
• enlarged prostate (BPH)
• hypothyroidism
• irregular heart rhythms
• narrowing of the urethra

If you have any of these conditions, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Seizures: Hydromorphone may worsen pre-existing seizure disorders. If tolerance to the medication develops and the dosage is increased substantially above recommended levels, seizures may occur in people without a history of seizure disorders. If you have a history of seizure disorders, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Serotonin Syndrome: Severe reactions are possible when hydromorphone is combined with other medications that act on serotonin, such as tricyclic antidepressants and serotonin reuptake inhibitors, medications used to treat depression. Symptoms of a reaction may include muscle rigidity and spasms, difficulty moving, changes in mental state including delirium and agitation. Coma and death are possible.

If you are taking antidepressants, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately. Infants born to mothers who have been taking hydromorphone for long periods of time or who are physically dependent on hydromorphone will also be physically dependent on the medication and may experience breathing difficulties as well as withdrawal symptoms.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking hydromorphone, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using hydromorphone have not been established for children.

Seniors: Seniors may be more sensitive to the effects of hydromorphone and may require lower doses to reduce the risk of side effects.

There may be an interaction between hydromorphone and any of the following:

• acetazolamide
• aclidinium
• alcohol
• amphetamines (e.g., dextroamphetamine, lisdexamfetamine)
• antihistamines that cause drowsiness (e.g., azelastine, cetirizine, doxylamine, chlorpheniramine, diphenhydramine, hydroxyzine, loratadine, rupatadine)
• antipsychotics (e.g., aripiprazole, chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
• atropine
• barbiturates (e.g., phenobarbital, butalbital, thiopental)
• benzodiazepines (e.g., lorazepam, diazepam, clonazepam)
• beta-blockers (e.g., atenolol, metoprolol)
• benztropine
• brimonidine
• buprenorphine
• cannabis
• chloral hydrate
• clidinium
• clonidine
• darifenacin
• desmopressin
• dimenhydrinate
• diphenoxylate
• disopyramide
• diuretics (water pills; e.g., furosemide, hydrochlorothiazide, triamterene)
• domperidone
• efavirenz
• eluxadoline
• entacapone
• eplerenone
• esketamine
• fesoterodine
• general anesthetics (medications used to put people to sleep before surgery)
• glycopyrrolate
• ipratropium
• kava kava
• ketotifen
• lemborexant
• linezolid
• lithium
• methadone
• metoclopramide
• mirtazapine
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, tranylcypromine, rasagiline, selegiline) taken within the past 14 days
• muscle relaxants (e.g., baclofen, cyclobenzaprine, methocarbamol, orphenadrine, tizanidine)
• nabilone
• naltrexone
• other opioid medications (e.g., fentanyl, morphine, codeine, oxycodone, butorphanol, tramadol)
• oxybutynin
• pegvisomant
•  pizotifen
• pomalidomide
• pregabalin
• quinidine
• ropinirole
• rotigotine
• scopolamine
• seizure medications (e.g., carbamazepine, clobazam, levetiracetam, phenobarbital, phenytoin, primidone, topiramate, valproic acid, zonisamide)
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
• serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., desvenlafaxine, duloxetine, venlafaxine)
• solifenacin
• somatostatin analogues (e.g., lanreotide, octreotide, pasireotide)
• tetrabenazine
• thalidomide
• tiotropium
• tolterodine
• trazodone
• tricyclic antidepressants (e.g., amitriptyline, desipramine)
• trihexyphenidyl
• trospium
• tryptophan
• umeclidinium
• zolpidem
• zopiclone

If you are taking any medications that have a sedating effect, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.