lactulose
Lactulose (Constulose) is a liquid osmotic laxative. It's used to help relieve constipation in adults. This medication is taken by mouth, typically once daily. Once you start treatment, it can take up to two days before you have a bowel movement. Some common side effects of lactulose (Constulose) include stomach pain and passing gas. There's a separate version of lactulose used for symptoms of a liver problem called hepatic encephalopathy.
What is Lactulose (Constulose)?
What is Lactulose (Constulose) used for?
How Lactulose (Constulose) works
Lactulose (Constulose) is an osmotic laxative. It eases constipation by drawing more fluid into the gut. This helps soften the stool and makes it easier to pass.
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What are the side effects of Lactulose (Constulose)?
Common Side Effects
- Passing gas
- Stomach cramps
Other Side Effects
- Nausea or vomiting
- Diarrhea
Source:Â DailyMed
The following side effects have also been reported
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
For bulk-forming-containing
Difficulty in breathing
intestinal blockage
skin rash or itching
swallowing difficulty (feeling of lump in throat)
For hyperosmotic-containing
Confusion
dizziness or light-headedness
irregular heartbeat
muscle cramps
unusual tiredness or weakness
For stimulant-containing
Confusion
irregular heartbeat
muscle cramps
pink to red, red to violet, or red to brown coloration of alkaline urine (for cascara, danthron, and/or senna only)
skin rash
unusual tiredness or weakness
yellow to brown coloration of acid urine (for cascara, and/or senna only)
For stool softener (emollient)-containing
Skin rash
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
For lubricant-containing
Skin irritation surrounding rectal area
For stool softener (emollient)-containing
Stomach and/or intestinal cramping
throat irritation (liquid forms only)
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Pros and cons of Lactulose (Constulose)
Pros
Can be used in people with kidney or liver problems
Might be a good option for people with constipation who didn’t see benefits with other laxatives
Available as a lower-cost generic medication
Side effects are mild and typically go away with time
Cons
Not a good option for people who are lactose intolerant
Not appropriate for people on a low-galactose diet
Not a first-choice laxative because of the side effects
Can take up to 2 days for you to have a bowel movement
Pharmacist tips for Lactulose (Constulose)
If you don't like the taste of lactulose (Constulose), try mixing it with fruit juice, water, or milk. Some people think this medication tastes better when mixed with one of these beverages.
Talk with your prescriber if you've questions about how lactulose (Constulose) might affect your blood sugar. Lactulose (Constulose) does contain galactose and lactose, which are two types of sugars. But limited research shows that lactulose (Constulose) isn't likely to raise your blood sugar levels.
Lactulose (Constulose) might cause diarrhea if your dose is too high. This can cause you to lose water and feel dehydrated, so make sure you drink enough fluids to make up for the loss. If you have diarrhea, let your healthcare team know. They can lower your dose of lactulose (Constulose) and let you know if you need more medical attention.
Don’t take antacids, like Mylanta Maximum Strength (aluminum hydroxide / magnesium hydroxide / simethicone) or calcium carbonate (Tums), at the same time as lactulose (Constulose). They might cause lactulose (Constulose) to not work as well. If you need medications for heartburn, ask your healthcare team about other options that won't interact with lactulose (Constulose).
If your lactulose (Constulose) solution didn't come with a measuring device, ask your local pharmacist for a device to use in order to measure out your doses. Don't use a household tablespoon because these can be inaccurate and cause you to take the wrong dose.
It's normal for lactulose (Constulose) solution to darken in color during storage at room temperature (between 36° to 86°F). This won't affect how well the medication works. But if you've stored lactulose (Constulose) at temperatures higher than 86°F for an extended period of time, then don't take it because it might not work as it should.
There aren't enough studies about whether lactulose (Constulose) is safe during pregnancy. But lactulose (Constulose) might not be appropriate to take during pregnancy because it can cause nausea and bloating, which can be very uncomfortable. If you have plans to get pregnant, ask your healthcare team about safer options to treat constipation.
Frequently asked questions about Lactulose (Constulose)
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What are the risks and warnings for Lactulose (Constulose)?
Lactulose (Constulose) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Loss of fluids
Risk factors: Taking lactulose (Constulose) for more than 6 months | Age 65 years and older | Taking medications that cause electrolyte imbalances
Lactulose (Constulose) can make you dehydrated which can affect your body's mineral levels. Electrolytes (minerals), such as sodium, potassium, and calcium, have many important functions in the body. Your healthcare professional (HCP) might want to check these regularly while you're taking lactulose (Constulose), especially if you’re older in age or have been taking lactulose (Constulose) for a long period of time. Call your HCP right away if you feel extremely thirsty, tired, or confused because these are signs that lactulose (Constulose) might be making you dehydrated and affecting your electrolyte levels.
Possible risk of high blood sugar
Risk factors: Diabetes
Be mindful that lactulose (Constulose) contains galactose and lactose, which are both forms of sugar. If you have high blood sugar, it's best to check your blood sugar levels regularly while taking lactulose (Constulose). Limited research show that lactulose (Constulose) doesn't seem to cause a spike in blood sugar, but you're still recommended to check your blood sugar levels just in case.
Problems during colonoscopy
If you're planning to have a colonoscopy or a rectal exam, let your healthcare team know you're taking lactulose (Constulose). Your HCP might have you take different medications to clean out your gut before your exam.
Lactulose (Constulose) dosage forms
Typical dosing for Lactulose (Constulose)
Each 15 mL of solution contains 10 grams of lactulose.
The typical dose is to take 15 mL to 30 mL by mouth daily. The maximum recommended dose is 60 mL daily.
Interactions between Lactulose (Constulose) and other drugs
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking any of these medicines, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using medicines in this class with any of the following medicines is not recommended. Your doctor may decide not to treat you with a medication in this class or change some of the other medicines you take.
- Amantadine
- Atropine
- Belladonna
- Belladonna Alkaloids
- Benztropine
- Bepridil
- Biperiden
- Burosumab-twza
- Cisapride
- Clidinium
- Darifenacin
- Dicyclomine
- Dronedarone
- Eplerenone
- Fesoterodine
- Glycopyrrolate
- Hyoscyamine
- Mesoridazine
- Methscopolamine
- Oxybutynin
- Pimozide
- Piperaquine
- Procyclidine
- Saquinavir
- Scopolamine
- Solifenacin
- Sparfloxacin
- Terfenadine
- Thioridazine
- Tolterodine
- Trihexyphenidyl
- Trospium
- Ziprasidone
Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Acalabrutinib
- Alacepril
- Alfuzosin
- Amiloride
- Amiodarone
- Amisulpride
- Amitriptyline
- Amoxapine
- Amphetamine
- Amygdalin
- Anagrelide
- Apomorphine
- Aripiprazole
- Aripiprazole Lauroxil
- Arsenic Trioxide
- Asenapine
- Astemizole
- Azathioprine
- Azithromycin
- Baloxavir Marboxil
- Bedaquiline
- Benazepril
- Benzphetamine
- Bictegravir
- Bisacodyl
- Bupivacaine
- Buprenorphine
- Buserelin
- Cabotegravir
- Canrenoate
- Captopril
- Ceritinib
- Chloroquine
- Chlorpromazine
- Cilazapril
- Ciprofloxacin
- Citalopram
- Clarithromycin
- Clofazimine
- Clomipramine
- Clozapine
- Crizotinib
- Cyclobenzaprine
- Cyclosporine
- Dabrafenib
- Dasatinib
- Deferoxamine
- Degarelix
- Delamanid
- Delapril
- Desipramine
- Deslorelin
- Deutetrabenazine
- Dextroamphetamine
- Digoxin
- Dimercaprol
- Disopyramide
- Dofetilide
- Dolasetron
- Dolutegravir
- Domperidone
- Donepezil
- Droperidol
- Efavirenz
- Eltrombopag
- Elvitegravir
- Encorafenib
- Entrectinib
- Erdafitinib
- Erythromycin
- Escitalopram
- Fingolimod
- Flecainide
- Fluconazole
- Fluoxetine
- Formoterol
- Foscarnet
- Fosinopril
- Fostemsavir
- Gatifloxacin
- Gefitinib
- Gemifloxacin
- Glasdegib
- Gonadorelin
- Goserelin
- Granisetron
- Halofantrine
- Haloperidol
- Histrelin
- Hyaluronidase
- Hydroxychloroquine
- Hydroxyzine
- Ibutilide
- Iloperidone
- Imidapril
- Imipramine
- Indomethacin
- Inotuzumab Ozogamicin
- Ivabradine
- Ivosidenib
- Ketoconazole
- Lamivudine
- Lapatinib
- Ledipasvir
- Lefamulin
- Lenvatinib
- Levofloxacin
- Levomethadyl
- Licorice
- Lisdexamfetamine
- Lisinopril
- Lofexidine
- Lopinavir
- Lumefantrine
- Macimorelin
- Mefenamic Acid
- Mefloquine
- Memantine
- Mercaptopurine
- Methadone
- Methamphetamine
- Metronidazole
- Mifepristone
- Mirtazapine
- Moexipril
- Moxifloxacin
- Mycophenolate Mofetil
- Mycophenolic Acid
- Nafarelin
- Neratinib
- Nilotinib
- Norfloxacin
- Nortriptyline
- Octreotide
- Ofloxacin
- Ondansetron
- Osilodrostat
- Osimertinib
- Oxaliplatin
- Ozanimod
- Paliperidone
- Panobinostat
- Pasireotide
- Pazopanib
- Pentopril
- Perindopril
- Phenytoin
- Pimavanserin
- Piperaquine
- Pitolisant
- Polyethylene Glycol 3350
- Ponesimod
- Posaconazole
- Procainamide
- Prochlorperazine
- Promethazine
- Propafenone
- Protriptyline
- Quetiapine
- Quinapril
- Quinidine
- Quinine
- Raltegravir
- Ramipril
- Ranolazine
- Ribociclib
- Rilpivirine
- Selpercatinib
- Senna
- Sertraline
- Sevoflurane
- Siponimod
- Sodium Picosulfate
- Sodium Polystyrene Sulfonate
- Solifenacin
- Sorafenib
- Sotalol
- Spirapril
- Spironolactone
- St John's Wort
- Sulpiride
- Sunitinib
- Tacrolimus
- Telavancin
- Telithromycin
- Temocapril
- Tetrabenazine
- Toremifene
- Trandolapril
- Trazodone
- Triamterene
- Triclabendazole
- Trifluoperazine
- Trimipramine
- Triptorelin
- Vandetanib
- Vardenafil
- Vemurafenib
- Vinflunine
- Vismodegib
- Voclosporin
- Voriconazole
- Zofenopril
- Zuclopenthixol
How much does Lactulose (Constulose) cost?
Lactulose (Constulose) contraindications
People on a low-galactose diet
What are alternatives to Lactulose (Constulose)?
Occasional constipation and irregular bowel movements
What is the latest news about Lactulose (Constulose)?
Lactulose (Constulose) images
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References
Best studies we foundBarish, C.F., et al. (2010). Comparison of preference and safety of powder and liquid lactulose in adult patients with chronic constipation. Clinical and Experimental Gastroenterology.
Bosch, A. M. (2011). Classic galactosemia: Dietary dilemmas. Journal of Inherited Metabolic Disease.
Center for Disease Control and Prevention. (2018). Spoons are for soup / Milliliters (mL) are for medicine.
Chartwell RX, LLC. (2024). LACTULOSE solution [package insert]. DailyMed.
Longo, S.A., et al. (2010). Gastrointestinal Conditions during Pregnancy. Clinics in Colon and Rectal Surgery.
Pieber, T. R., et al. (2021). Blood glucose response after oral lactulose intake in type 2 diabetic individuals. World Journal of Diabetes.
Steudle, J., et al. (2018). Blood glucose response after oral intake of lactulose in healthy volunteers: A randomized, controlled, cross-over study. World Journal of Gastrointestinal Pharmacology and Therapeutics.
WĹ‚odarczyk, J., et al. (2021). Current overview on clinical management of chronic constipation. Journal of Clinical Medicine.
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