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Jenloga Side Effects

Generic Name: clonidine

Note: This page contains information about the side effects of clonidine. Some of the dosage forms included on this document may not apply to the brand name Jenloga.

For the Consumer

Applies to clonidine: oral suspension extended release, oral tablet, oral tablet extended release

In addition to its needed effects, some unwanted effects may be caused by clonidine (the active ingredient contained in Jenloga). In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking clonidine:

Less common:
  • Mental depression
  • swelling of the feet and lower legs
  • Anxiety
  • blistering, burning, crusting, dryness, or flaking of the skin
  • chest pain or discomfort
  • confusion as to time, place, or person
  • decreased urine output
  • dilated neck veins
  • drowsiness
  • dry mouth
  • fast, pounding, or irregular heartbeat or pulse
  • fever
  • general feeling of discomfort or illness
  • holding false beliefs that cannot be changed by fact
  • hyperventilation
  • irregular breathing
  • irritability
  • itching, scaling, severe redness, soreness, or swelling of the skin
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • lightheadedness, dizziness, or fainting
  • mental depression
  • paleness or cold feeling in the fingertips and toes
  • pounding, slow heartbeat
  • problems in urination or increase in the amount of urine
  • raised red swellings on the skin, lips, tongue, or in the throat
  • restlessness
  • seeing or hearing things that are not there
  • shaking
  • shortness of breath
  • skin rash
  • swelling of the face, fingers, feet, or lower legs
  • tightness in the chest
  • tingling or pain in the fingers or toes when exposed to cold
  • trouble with sleeping
  • troubled breathing
  • unusual excitement, nervousness, or restlessness
  • unusual tiredness or weakness
  • vivid dreams or nightmares
  • weight gain
  • wheezing

If any of the following symptoms of overdose occur while taking clonidine, get emergency help immediately:

Symptoms of overdose:
  • Dizziness (extreme) or faintness
  • feeling cold
  • pinpoint pupils of the eyes
  • unusual tiredness or weakness (extreme)

Minor Side Effects

Some of the side effects that can occur with clonidine may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Constipation
Less common:
  • Darkening of the skin
  • decreased sexual ability
  • dry, itching, or burning eyes
  • loss of appetite
  • nausea or vomiting
  • Blurred vision
  • decreased interest in sexual intercourse
  • hair loss or thinning of the hair
  • inability to have or keep an erection
  • leg cramps
  • loss in sexual ability, desire, drive, or performance
  • muscle or joint pain
  • pale skin
  • swelling of the breasts or breast soreness in both females and males
  • weakness

For Healthcare Professionals

Applies to clonidine: compounding powder, injectable solution, oral suspension extended release, oral tablet, oral tablet extended release, transdermal film extended release


The most common adverse side effects are related to the alpha-adrenergic blocking effects of clonidine (the active ingredient contained in Jenloga) These side effects are dose-related, typically decrease over time, and mostly affect the nervous system, cardiovascular system, and the gastrointestinal system.[Ref]

Nervous system

Nervous system side effects have included drowsiness (28%), dizziness (9%), somnolence (19%), fatigue (13%), headache (19%), irritability (6%), insomnia (6%), nightmares (3%), body temperature increased (1%), abnormal sleep-related event (1%), and tremor (3%). Patients with decreased autoregulation of cerebral blood flow appear to be at increased risk for clonidine-induced cerebral hypoperfusion if blood pressure is lowered too much or too quickly. This may be important in some elderly patients. Confusion (13.2%) and hallucinations (5.3%) have been reported with epidural usage. Dose-dependent sedative effects, memory impairment, and reduced cognitive performance have been reported in subjects receiving intravenous clonidine (the active ingredient contained in Jenloga) [Ref]

A study of 13 patients who had pre- and post-clonidine cerebral blood flow (CBF) measured by nuclear scanning revealed that patients with an initially high pretreatment CBF tended to demonstrate decreased CBF after clonidine therapy.

Patients with traumatic spinal cord injury receiving clonidine may experience a delayed-onset of sedation regardless of the route of administration (i.e., intrathecal, intramuscular).[Ref]


Cardiovascular side effects have included hypotension and sinus and atrioventricular arrhythmias. Postural hypotension occurs in 2% of patients. Rebound hypertension (which may be worse than pretreatment values) can present as irritability, tremors, headache, increased salivation, and palpitations. Rebound hypertension may be minimized by gradual reduction of dosage over two to four days.

Hypotension with epidural clonidine (the active ingredient contained in Jenloga) has been reported in 45% of 38 patients in one study. Hypotension occurred more commonly in the first four days, in women, in lower weight patients, and those receiving higher dosages.

Other cardiovascular side effects have included sinus bradycardia in approximately 0.3% of patients. A rare case of sinus arrest associated with clonidine has been reported. Patients with preexisting sinus node dysfunction, patients who have developed bradycardia while taking other sympatholytic agents, patients who are on another sympatholytic agent, and patients with renal dysfunction are at increased risk of clonidine-associated sinus bradycardia. Clonidine may cause hypertension in some patients with idiopathic orthostatic hypotension, particularly those with autonomic nervous system dysfunction. There have also been reports of congestive heart failure, electrocardiographic abnormalities (i.e., sinus node arrest, junctional bradycardia, high degree AV block, and arrhythmias), palpitations, Raynaud's phenomenon, syncope, and tachycardia. Cases of sinus bradycardia and atrioventricular block have been reported, both with and without the use of concomitant digitalis.[Ref]

A case of sinus arrest associated with clonidine has been reported. A 65-year-old man with diabetes, hypertension and unexplained syncope developed more frequent syncope and dizziness associated with documented episodes of sinus arrest during the first week of clonidine therapy. The patient had no hypoglycemia or orthostatic changes. The syncope and dizziness resolved upon discontinuation of clonidine; continuous electrocardiographic monitoring revealed a gradual and complete disappearance of sinus pauses. Junctional bradycardia and AV heart block have also been reported.

Ventricular tachycardia (VT) relatively refractory to lidocaine, but responsive to intravenous phentolamine, has been associated with clonidine withdrawal (case report). The authors believe that the VT was probably produced by humoral or neural stimulation of unregulated myocardial alpha-adrenergic receptors.

Transdermal clonidine has been implicated with hypertension in a quadriplegic patient with a C4 spinal lesion. The proposed mechanism is predominance of clonidine's peripheral alpha-1 adrenergic effects due to the patient's autonomic dysfunction, resulting in vasoconstriction and hypertension.

Sinus bradycardia or other supraventricular bradyarrhythmias are more likely in patients with underlying renal dysfunction.

In one case report, severe hypotension occurred during separation from cardiopulmonary bypass in a patient given intrathecal clonidine. The patient responded to volume expansion and use of vasoconstrictors.[Ref]


Gastrointestinal side effects have most commonly included dry mouth (30%) and constipation (15%), abdominal pain, anorexia, nausea, vomiting, diarrhea (1%), parotitis, pseudo-obstruction (including colonic pseudo-obstruction), and salivary gland pain. Nausea (13.2%) and vomiting (10.5%) have been reported with epidural clonidine (the active ingredient contained in Jenloga) [Ref]


Genitourinary side effects have included impotence in male patients (24%), retrograde and delayed ejaculation, and an inability to achieve orgasm in female patients.[Ref]


A 66-year-old woman with a history of psoriasis in remission developed erythematous, scaly plaques on the extensor surfaces of her forearms within three days after beginning clonidine (the active ingredient contained in Jenloga) therapy for control of flushing. The author of this case report suspected that clonidine may cause a fall in intracellular cAMP, leading to epidermal cell proliferation, and, in some cases, a psoriasiform eruption.[Ref]

Dermatologic reactions have been reported in 10% to 38% of patients who use transdermal clonidine. These reactions include psoriasis exacerbations, local dermatitis and/or pigmentation, alopecia, angioneurotic edema, hives, pruritus, rash, and urticaria.[Ref]


Psychiatric side effects have included emotional disorder (5%), aggression (1%), tearfulness (3%) and rare reports of depression, which has been the most common psychiatric reaction to clonidine (the active ingredient contained in Jenloga) Rare cases of frank psychoses and delirium have been associated with clonidine withdrawal. Hallucinations have been reported postmarketing.[Ref]


Endocrinologic side effects have been limited to rare cases of gynecomastia, hyperprolactinemia, or hyperglycemia.[Ref]

A 68-year-old black man with hypertension, status post unilateral nephrectomy, was incidentally found to have 4+ proteinuria, 1+ glycosuria, new elevated blood glucose levels, and between 1.8 and 5.4 grams of protein per 24-hour urine collection within 6 weeks after starting clonidine. The signs and symptoms of diabetes and the nephrotic syndrome disappeared within five months after discontinuation of clonidine. Because of his solitary kidney, a renal biopsy was not performed.[Ref]


Musculoskeletal side effects have included leg cramps and muscle or joint pain. Moderately severe myalgia has been associated with the use of clonidine (the active ingredient contained in Jenloga) in patients treated for opioid withdrawal symptoms.[Ref]


Immunologic side effects have rarely been reported and include one case of immune-complex disease.[Ref]

A 46-year-old woman developed forearm edema, mild thenar atrophy, and skin hypopigmentation within three months after beginning clonidine for perimenopausal flushing. Electromyelography was consistent with carpal tunnel syndrome. At surgical decompression, a skin biopsy revealed changes consistent with immune-complex disease. The patient's signs and symptoms abated after physical therapy and discontinuation of clonidine.[Ref]


Respiratory system reactions have included nasal congestion (5%), asthma (1%), and nasopharyngitis (3%). A case of severe bronchospasm associated with clonidine (the active ingredient contained in Jenloga) has been reported in the pediatric literature.[Ref]

A 9-year-old boy with asthma developed a severe asthma attack after an oral clonidine stimulation test. He required hospitalization. The authors of this case report suspect that clonidine may have caused acute pulmonary artery vasoconstriction (directly), which could have decreased pulmonary blood flow, producing relative pulmonary hypoxemia, setting off an asthma attack.[Ref]


Ocular side effects have included accommodation disorder, blurred vision, burning of the eyes, decreased lacrimation, and dryness of the eyes.


Metabolic side effects have included thirst (3%) and throat pain (6%).


1. Gourlay SG, Benowitz NL "Is clonidine an effective smoking cessation therapy?" Drugs 50 (1995): 197-207

2. Keranen A, Nykanen S, Taskinen J "Pharmacokinetics and side-effects of clonidine." Eur J Clin Pharmacol 13 (1978): 97-101

3. Kosman ME "Evaluation of clonidine hydrochloride (catapres): a new antihypertensive agent." JAMA 233 (1975): 174-6

4. Anavekar SN, Jarrott B, Toscano M, Louis WJ "Pharmacokinetic and pharmacodynamic studies of oral clonidine in normotensive subjects." Eur J Clin Pharmacol 23 (1982): 1-5

5. Greene CS, Gretler DD, Cervenka K, et al "Cerebral blood flow during the acute therapy of severe hypertension with oral clonidine." Am J Emerg Med 8 (1990): 293-6

6. Hall JE, Uhrich TD, Ebert TJ "Sedative, analgesic and cognitive effects of clonidine infusions in humans." Br J Anaesth 86 (2001): 5-11

7. Kostis JB, Rosen RC, Holzer BC, et al "CNS side effects of centrally-active antihypertensive agents: a prospective, placebo-controlled study of sleep, mood state, and cognitive and sexual function in hypertensive males." Psychopharmacology (Berl) 102 (1990): 163-70

8. Eisenach JC, Dupen S, Dubois M, Miguel R, Allin D, Bryce D, Burger GA, Chamberlain D, Docherty R, Evans G, Finnegan R, Hantler "Epidural clonidine analgesia for intractable cancer pain." Pain 61 (1995): 391-9

9. Ferder L, Inserra F, Medina F "Safety aspects of long-term antihypertensive therapy (10 years) with clonidine." J Cardiovasc Pharmacol 10 (1987): s104-8

10. Filos KS, Patroni O, Goudas LC, Bosas O, Kassaras A, Gartaganis S "A dose-response study of orally administered clonidine as premedication in the elderly - evaluating hemodynamic safety." Anesth Analg 77 (1993): 1185-92

11. Malinovsky JM, Malinge M, Lepage JY, Pinaud M "Sedation caused by clonidine in patients with spinal cord injury." Br J Anaesth 90 (2003): 742-745

12. Leckman JF, Ort S, Caruso KA, et al "Rebound phenomena in Tourette's syndrome after abrupt withdrawal of clonidine: behavioral, cardiovascular, and neurochemical effects." Arch Gen Psychiatry 43 (1986): 1168-76

13. "Product Information. Duraclon Injection (clonidine)" Roxane Laboratories Inc, Columbus, OH.

14. Pettinger WA "Clonidine, a new antihypertensive drug." N Engl J Med 293 (1975): 1179-80

15. Golusinski LL, Blount BW "Clonidine-induced bradycardia." J Fam Pract 41 (1995): 399-401

16. Puskas F, Camporesi EM, O'Leary CE, Hauser M, Nasrallah FV "Intrathecal clonidine and severe hypotension after cardiopulmonary bypass." Anesth Analg 97 (2003): 1251-3

17. Whitsett TL, Chrysant SG, Dillard BL, Anton AH "Abrupt cessation of clonidine administration: a prospective study." Am J Cardiol 41 (1978): 1285-90

18. Young E, Levey BA, Shapiro AP "Paradoxical hypertension from clonidine ." Ann Intern Med 101 (1984): 282-3

19. van Zwieten PA, Thoolen MJ, Timmermans PB "The hypotensive activity and side effects of methyldopa, clonidine, and guanfacine." Hypertension 6 (1984): 28-33

20. Levitan D, Massry SG, Romoff M, Campese VM "Plasma catecholamines and autonomic nervous system function in patients with early renal insufficiency and hypertension: effect of clonidine." Nephron 36 (1984): 24-9

21. Bruce D, Croley T, Lee J "Preoperative clonidine withdrawal syndrome." Anesthesiology 51 (1979): 90-2

22. Robertson D, Goldberg MR, Hollister AS, et al "Clonidine raises blood pressure in severe idiopathic orthostatic hypotension." Am J Med 74 (1983): 193-200

23. Stewart M, Burris JF "Rebound hypertension during initiation of transdermal clonidine." Drug Intell Clin Pharm 22 (1988): 573-4

24. Byrd BF, Collins HW, Primm RK "Risk factors for severe bradycardia during oral clonidine therapy for hypertension." Arch Intern Med 148 (1988): 729-33

25. Given BD, Taylor T, Lilly LS, Dzau VJ "Symptomatic hypotension following the clonidine suppression test for pheochromocytoma." Arch Intern Med 143 (1983): 2195-6

26. Fruncillo RJ, Gibbons WJ, Vlasses PH, Ferguson RK "Severe hypotension associated with concurrent clonidine and antipsychotic medication." Am J Psychiatry 142 (1985): 274

27. Schwartz E, Friedman E, Mouallem M, Farfel Z "Sinus arrest associated with clonidine therapy." Clin Cardiol 11 (1988): 53-4

28. Maloney MJ, Schwam SJ "Clonidine and sudden death." Pediatrics 96 (1995): 1176-7

29. Backo AL, Clause SL, Triller DM, Gibbs KA "Clonidine-induced hypertension in a patient with a spinal lesion." Ann Pharmacother 36 (2002): 1396-8

30. Strauss F, Franklin S, Lewin A, Maxwell M "Withdrawal of antihypertensive therapy." JAMA 238 (1977): 1734-36

31. Moss HB, Procci WR "Sexual dysfunction associated with oral antihypertensive medication: a critical survey of the literature." Gen Hosp Psychiatry 4 (1982): 121-9

32. Stevenson JG, Umstead GS "Sexual dysfunction due to antihypertensive agents." Drug Intell Clin Pharm 18 (1984): 113-21

33. Beeley L "Drug-induced sexual dysfunction and infertility." Adverse Drug React Acute Poisoning Rev 3 (1984): 23-42

34. Hodge RH, Harward MP, West MS, et al "Sexual function of women taking antihypertensive agents: a comparative study." J Gen Intern Med 6 (1991): 290-4

35. Corazza M, Mantovani L, Virgili A, Strumia R "Allergic contact dermatitis from a clonidine transdermal delivery system." Contact Dermatitis 32 (1995): 246

36. Dick JB, Northridge DB, Lawson AA "Skin reactions to long-term transdermal clonidine ." Lancet 1 (1987): 516

37. Wiser TH, Kazakis AM, LaCivita CL "Transdermal clonidine: an association with recurrent herpes simplex and hyperpigmentation ." J Am Acad Dermatol 17 (1987): 143-4

38. "Allergic skin reactions to transdermal clonidine ." Lancet 2 (1983): 850-1

39. Doe N, Seth S, Hebert LA "Skin depigmentation related to transdermal clonidine therapy." Arch Intern Med 155 (1995): 2129

40. Boekhorst JC "Allergic contact dermatitis with transdermal clonidine ." Lancet 2 (1983): 1031-2

41. Wilkin J "Exacerbation of psoriasis during clonidine therapy ." Arch Dermatol 117 (1981): 4

42. Tom GR "Hydrocortisone cream in clonidine patch dermatitis." Ann Pharmacother 28 (1994): 889-90

43. Brown MJ, Salmon D, Rendell M "Clonidine hallucinations." Ann Intern Med 93 (1980): 456-7

44. Prasad A, Shotliff K "Depression and chronic clonidine therapy." Postgrad Med J 69 (1993): 327-8

45. Adler LE, Bell J, Kirch D, et al "Psychosis associated with clonidine withdrawal." Am J Psychiatry 139 (1982): 110-2

46. Fein G, Merrin EL, Davenport L, Buffum JC "Memory deficits associated with clonidine." Gen Hosp Psychiatry 9 (1987): 154-5

47. Mendhekar DN "Clonidine-Induced Gynecomastia and Hyperprolactinemia in a 6-Year-Old Child." J Clin Psychiatry 66 (2005): 1616-1617

48. Mimouni-Bloch A, Mimouni M "Clonidine-induced hyperglycemia in a young diabetic girl." Ann Pharmacother 27 (1993): 980

49. Schwarz KO "Clonidine-induced myalgia ." Med J Aust 147 (1987): 365

50. Petersen HH, Hansen M, Albrectsen JM "Clonidine-induced immune complex disease." Acta Derm Venereol 69 (1989): 519-20

51. "Product Information. Catapres (clonidine)." Boehringer-Ingelheim, Ridgefield, CT.

Not all side effects for Jenloga may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

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