chloroquine phosphate
Chloroquine works well to prevent and treat certain types of malaria. But it can cause serious side effects, such as heart rhythm problems.
What is Chloroquine?
What is Chloroquine used for?
- Treatment of uncomplicated malaria
- Prevention of malaria in areas of the world where there's no chloroquine resistance
- Extraintestinal amebiasis (a type of parasitic infection)
How Chloroquine works
Chloroquine is an anti-malarial medication. It works by interfering with certain processes that the malaria-causing parasites need to grow.
Drug facts
Side effects of Chloroquine
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
- Nausea
- Vomiting
- Diarrhea
- Stomach cramps
- Headache
- Rash
- Itching
Less Common Side Effects
- Tiredness
- Confusion
- Anxiety
- Hallucinations (hearing or seeing things that aren't there)
- Muscle weakness
Chloroquine serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Seizures
- Changes in vision: blurry vision, only seeing half of an object, difficulty focusing, trouble seeing things at night
- Irregular heartbeat (QT prolongation): dizziness, feeling lightheaded, blurry vision, pounding heart, fainting
- Dangerously low blood sugar: feeling anxious, sweating, shaking, confusion, dizziness, weakness, fast heartbeat, feeling hungry, coma
- Serious skin reactions: fever, tiredness, body aches, blistering rash, peeling skin
The following Chloroquine 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 immediately if any of the following side effects occur:
Incidence not known
attempts at killing oneself
back, leg, or stomach pains
black, tarry stools
bleeding gums
blistering, peeling, or loosening of the skin
blood in the urine or stools
blurred or decreased vision
change in near or distance vision
chest discomfort or pain
chills
cold sweats
confusion
continuing ringing or buzzing or other unexplained noise in the ears
dark urine
difficulty in focusing the eyes
difficulty with speaking
difficulty with swallowing
disturbed color perception
dizziness
dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
double vision
fast, slow, irregular, or pounding heartbeat
feeling that others are watching you or controlling your behavior
feeling that others can hear your thoughts
feeling, seeing, or hearing things that are not there
general tiredness and weakness
halos around lights
headache
hearing loss
inability to move the eyes
increased blinking or spasms of the eyelid
joint or muscle pain
large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
light-colored stools
loss of balance control
lower back or side pain
muscle trembling, jerking, or stiffness
muscular pain, tenderness, wasting, or weakness
night blindness
overbright appearance of lights
painful or difficult urination
pale skin
pinpoint red spots on the skin
puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
red skin lesions, often with a purple center
red, irritated eyes
restlessness
shuffling walk
sores, ulcers, or white spots on the lips or in the mouth
sticking out of the tongue
stiffness of the limbs
sweating
swollen or painful glands
tightness in the chest
trouble breathing
tunnel vision
twitching, twisting, or uncontrolled repetitive movements of the tongue, lips, face, arms, or legs
uncontrolled movements, especially of the face, neck, and back
unusual bleeding or bruising
unusual tiredness or weakness
upper right abdominal or stomach pain
vomiting
yellow eyes and skin
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
Cold, clammy skin
decreased urine
drowsiness
fast, weak pulse
increased thirst
lightheadedness, dizziness, or fainting
loss of appetite
muscle pain or cramps
numbness or tingling in the hands, feet, or lips
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:
Incidence not known
Change in hair color
increased sensitivity of the skin to sunlight
redness or other discoloration of the skin
severe sunburn
stomach cramps
trouble sleeping
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.
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Pros and cons of Chloroquine
Pros
- Generally safe to use for malaria prevention and treatment during pregnancy
- Can be taken by children
- Can take with or without food
- Available as a lower-cost generic
Cons
- Should be taken 2 weeks before traveling to an area with malaria, compared to some alternatives that can be taken 1-2 days before
- Only works well against malaria from certain areas of the world
- Can't treat severe malaria
- Can worsen conditions, such as psoriasis or seizures
Pharmacist tips for Chloroquine
- Make sure to take chloroquine according to the instructions given by your healthcare provider. If you're taking chloroquine for malaria prevention, you'll need to continue the medication even after you've left the area at risk for malaria.
- If chloroquine upsets your stomach, taking it with food can help.
- If you take an antacid (such as calcium carbonate (TUMS)), take it at least 4 hours apart from chloroquine because antacids can make this medication not work as well.
- If you have high blood sugar and are taking medications that lower your blood sugar levels, such as insulin, let your provider know. Taking this type of medication at the same time as Chloroquine can raise your risk for experiencing dangerously low blood sugar. Your provider might ask you to check your blood sugar levels more often. Keep fast-acting sugars with you at all times so you can bring your blood sugar level back up to a safe range if needed. Symptoms of low blood sugar include shakiness, hunger, and feeling irritable.
- It's best to avoid or limit the amount of alcohol you drink while taking chloroquine. Drinking alcohol with chloroquine can raise your chances of liver problems. If you drink alcohol regularly, let your provider know. They can help recommend an amount of alcohol that's safer to drink.
- If you experience tremors (shaking) or uncontrollable movements while taking chloroquine, let your provider know right away. This might be a rare, but serious side effect of chloroquine.
- Tell your provider if you have trouble hearing after starting chloroquine. This medication can cause damage to your ears and affect your hearing. Your provider might ask you to stop taking chloroquine if they think your hearing problem is caused by this medication.
- Keep chloroquine up and away from children and pets. Small amounts have caused accidental deaths in children. If your child accidentally swallowed this medication and it's not prescribed to them, call a Poison Center right away at 1-800-222-1222.
Common questions about Chloroquine
Chloroquine and hydroxychloroquine (Plaquenil) are slightly different medications that share a similar chemical structure. They're both approved for the prevention and treatment of malaria. But hydroxychloroquine (Plaquenil) is also approved for rheumatoid arthritis and lupus, while chloroquine isn't. People might experience more side effects with chloroquine compared to hydroxychloroquine (Plaquenil).
Let your provider know if you're pregnant or thinking about becoming pregnant. Limited studies show that babies born to mothers who took the recommended doses of chloroquine for either malaria prevention or treatment didn't experience a higher risk for birth defects or other serious harm. Currently, the CDC's guidelines say that chloroquine can be taken by pregnant or nursing mothers.
There's no set length of time for when you need to stop taking chloroquine. But if you plan to travel to and stay in an area with malaria for a long time, let your provider know. Taking chloroquine for a long time (typically 5 years or longer) can put you at higher risk for certain side effects, such as vision problems or muscle weakness. Your provider might ask you to arrange with a local healthcare clinic to get yearly eye exams and other check ups to make sure chloroquine is still safe for you to take.
Data shows that chloroquine is not effective in treating COVID-19, lowering the likelihood of death, or speeding up recovery. In fact, it did more harm than good in clinical studies. This led the FDA to end its original emergency use authorization of chloroquine for COVID-19.
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Risks and warnings for Chloroquine
Chloroquine 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.
Heart problems
- Risk factors: Taking other medications that affect heart rhythm | High doses | Existing heart condition
Some people have experienced serious heart problems, such as heart rhythm problems, when taking chloroquine. The risk is higher if you're taking higher doses of chloroquine or other medications that affect your heart rhythm. Let your provider know if you have heart problems because they might consider other medications for you. If you feel dizzy, lightheaded, or have blurry vision, get medical care right away. Your provider might ask you to stop taking chloroquine.
Low blood sugar
- *Risk factors: Taking other medications that lower blood sugar *
Chloroquine can lower your blood sugar to dangerously low levels, which can be life-threatening. This can happen even if you're not taking other blood sugar medications.
Signs of low blood sugar include fast heartbeat, sweating, pale skin, shakiness, confusion, and irritability. You should carry some fast-acting sugar with you when you're taking chloroquine so you can raise your blood sugar whenever needed. Let your provider know if you experience low blood sugar while taking chloroquine because they might consider other medications for you.
Muscle weakness and nerve problems
- Risk factors: Taking chloroquine for a long time
Some people reported muscle weakness while taking chloroquine. Your provider will test your muscle strength and reflexes for signs of weakness if you need to take this medication for a long time. If you notice weakness in your muscles, talk to your provider because they might ask you to stop taking chloroquine.
Worsening of psoriasis and porphyria
People with psoriasis or porphyria might experience a severe worsening of their condition when taking chloroquine. If you have psoriasis or porphyria, let your healthcare provider know before starting this medication.
Hearing damage
- Risk factors: History of hearing problems
Chloroquine can cause damage to your hearing, especially if you already have problems with your hearing. If you notice ringing in your ears or any changes in your hearing, stop taking chloroquine and talk to your provider right away.
Low blood counts
- Risk factors: glucose-6-phosphate dehydrogenase (G6PD) deficiency
Chloroquine can affect blood counts. Your risk might be higher if you have a condition called G6PD deficiency. If you need to take this medication for a long period of time, your provider might order blood test to make sure your blood count is within a safe range.
Liver or kidney damage
- Risk factors: Taking other medications that affect the liver | Alcoholism | Existing liver or kidney conditions
Chloroquine is processed in the liver and can potentially be harmful to the liver, especially if you have existing liver conditions. Drinking alcohol with this medication can also raise your chances of liver problems. Talk to your provider about these concerns.
Additionally, kidney damage has happened to some people who took chloroquine. If you're urinating less than usual or notice swelling in your body, let your provider know since these can be signs your kidneys aren't working well.
Seizures
- Risk factors: History of epilepsy
Chloroquine might raise the risk of seizures in people who've experienced seizures in the past. Let your provider know if you've had past seizures because they might choose a different malaria medication for you.
Serious eye damage
- Risk factors: Taking higher doses or chloroquine | Taking chloroquine for 5 years or longer | Kidney damage | Taking other medications that can cause vision problems | Eye problems
Though rare, chloroquine vision changes or eye damage. Your risk might be higher if you take chloroquine for 5 years or longer or if you have vision problems. Sometimes, vision changes can worsen even after stopping the medication. Your provider might ask you to get an eye exam before you start chloroquine. Let your provider know right away if you notice any changes to your vision because they might need to check your vision more often.
Chloroquine dosage
Tablet| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 250mg | 30 tablets | $63.67 | $2.12 |
| 500mg | 7 tablets | $51.11 | $7.30 |
Typical dosage for Chloroquine
Malaria prevention
Ideally, your provider will have you start chloroquine 2 weeks before you travel to areas with malaria. Usually, you'll continue taking it while there and for 2 months after your return.
- Adults: The typical dose is 500 mg by mouth weekly on the same day each week.
- Children: Your child's provider will calculate the dose based on your child's body weight. It's typically given by mouth weekly on the same day each week.
If you're not able to start chloroquine 2 weeks before traveling, your provider will ask you take 2 doses of chloroquine (500 mg for adults and weight-based dose for children) 6 hours apart on the first day you start the medication.
Malaria treatment
- Adults: The typical dose is 1 gram by mouth, followed by 500 mg 6 to 8 hours later. After that, you'll take 500 mg once daily for the next two days.
- Children: Your child's provider will calculate the dose based on your child's body weight. Typically, your child will take a higher loading dose for their first dose. Then, they'll take a lower maintenance dose at 6 hours, 24 hours, and 36 hours after their loading dose.
If you have certain malaria parasites (P. vivax and P. ovale), your provider might also have you take another medication along with chloroquine to really get rid of the parasites.
Extraintestinal amebiasis
- Adults: The typical dose is 1 gram by mouth daily for 2 days, then 500 mg daily for at least 2 to 3 weeks. Your provider might have you take another medication along with chloroquine.
Interactions between Chloroquine 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 this medicine, 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 this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
- Aurothioglucose
- Bepridil
- Cisapride
- Dronedarone
- Levomethadyl
- Mesoridazine
- Pimozide
- Piperaquine
- Saquinavir
- Sparfloxacin
- Terfenadine
- Thioridazine
- Ziprasidone
Using this medicine 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.
- Acarbose
- Acecainide
- Agalsidase Alfa
- Ajmaline
- Albiglutide
- Alfuzosin
- Alogliptin
- Amiodarone
- Amisulpride
- Amitriptyline
- Amoxapine
- Anagrelide
- Apomorphine
- Aprindine
- Aripiprazole
- Aripiprazole Lauroxil
- Arsenic Trioxide
- Asenapine
- Astemizole
- Atazanavir
- Azimilide
- Azithromycin
- Bedaquiline
- Bretylium
- Buprenorphine
- Buserelin
- Canagliflozin
- Carbamazepine
- Ceritinib
- Chloral Hydrate
- Chlorpromazine
- Chlorpropamide
- Cimetidine
- Citalopram
- Clarithromycin
- Clofazimine
- Clomipramine
- Clozapine
- Crizotinib
- Cyclobenzaprine
- Dabrafenib
- Dapagliflozin
- Dasatinib
- Degarelix
- Delamanid
- Desipramine
- Deslorelin
- Deutetrabenazine
- Dibenzepin
- Disopyramide
- Dofetilide
- Dolasetron
- Domperidone
- Donepezil
- Doxepin
- Droperidol
- Dulaglutide
- Ebastine
- Efavirenz
- Empagliflozin
- Encorafenib
- Enflurane
- Entrectinib
- Eribulin
- Erythromycin
- Escitalopram
- Exenatide
- Famotidine
- Felbamate
- Fingolimod
- Flecainide
- Fluconazole
- Fluoxetine
- Formoterol
- Foscarnet
- Fosphenytoin
- Fostemsavir
- Galantamine
- Gatifloxacin
- Gemifloxacin
- Glasdegib
- Glimepiride
- Glipizide
- Glyburide
- Gonadorelin
- Goserelin
- Granisetron
- Halofantrine
- Haloperidol
- Halothane
- Histrelin
- Hydroquinidine
- Hydroxychloroquine
- Hydroxyzine
- Ibutilide
- Iloperidone
- Imipramine
- Inotuzumab Ozogamicin
- Insulin
- Insulin Aspart, Recombinant
- Insulin Bovine
- Insulin Degludec
- Insulin Detemir
- Insulin Glulisine
- Insulin Lispro, Recombinant
- Isoflurane
- Isradipine
- Itraconazole
- Ivabradine
- Ivosidenib
- Ketoconazole
- Lapatinib
- Lefamulin
- Lenvatinib
- Levofloxacin
- Lidoflazine
- Linagliptin
- Liraglutide
- Lixisenatide
- Lofexidine
- Lopinavir
- Lumefantrine
- Macimorelin
- Mefloquine
- Metformin
- Methadone
- Methotrimeprazine
- Metronidazole
- Mifepristone
- Miglitol
- Mirtazapine
- Mizolastine
- Moricizine
- Moxifloxacin
- Nafarelin
- Nateglinide
- Nelfinavir
- Nilotinib
- Norfloxacin
- Nortriptyline
- Octreotide
- Ofloxacin
- Olanzapine
- Ondansetron
- Osilodrostat
- Osimertinib
- Oxaliplatin
- Ozanimod
- Paliperidone
- Panobinostat
- Papaverine
- Paroxetine
- Pasireotide
- Pazopanib
- Pentamidine
- Perphenazine
- Pimavanserin
- Pioglitazone
- Pirmenol
- Pitolisant
- Pixantrone
- Ponesimod
- Posaconazole
- Prajmaline
- Pramlintide
- Probucol
- Procainamide
- Prochlorperazine
- Promethazine
- Propafenone
- Protriptyline
- Quetiapine
- Quinidine
- Quinine
- Rabies Vaccine
- Ranolazine
- Remdesivir
- Repaglinide
- Ribociclib
- Risperidone
- Ritonavir
- Rosiglitazone
- Saxagliptin
- Selpercatinib
- Semaglutide
- Sematilide
- Sertindole
- Sertraline
- Sevoflurane
- Siponimod
- Sitagliptin
- Sodium Phosphate
- Sodium Phosphate, Dibasic
- Sodium Phosphate, Monobasic
- Solifenacin
- Sorafenib
- Sotalol
- Spiramycin
- Sulfamethoxazole
- Sulpiride
- Sultopride
- Sunitinib
- Tacrolimus
- Tamoxifen
- Tedisamil
- Telaprevir
- Telavancin
- Telithromycin
- Tetrabenazine
- Tolazamide
- Tolbutamide
- Toremifene
- Trazodone
- Triclabendazole
- Trifluoperazine
- Trimethoprim
- Trimipramine
- Triptorelin
- Vandetanib
- Vardenafil
- Vemurafenib
- Venlafaxine
- Vilanterol
- Vildagliptin
- Vinflunine
- Voclosporin
- Voriconazole
- Vorinostat
- Zolmitriptan
- Zotepine
- Zuclopenthixol
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Aluminum Carbonate, Basic
- Aluminum Hydroxide
- Aluminum Phosphate
- Ampicillin
- Calcium Carbonate
- Ciprofloxacin
- Cyclosporine
- Digoxin
- Dihydroxyaluminum Aminoacetate
- Dihydroxyaluminum Sodium Carbonate
- Kaolin
- Magaldrate
- Magnesium Carbonate
- Magnesium Hydroxide
- Magnesium Oxide
- Magnesium Trisilicate
- Praziquantel
- Sodium Bicarbonate
How much does Chloroquine cost?
$51.11
Chloroquine contraindications
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Chloroquine will not be safe for you to take.
- Current eye changes or problems
What are alternatives to Chloroquine?
News about Chloroquine
Chloroquine images
