Clove may increase the risk of bleeding or potentiate the effects of warfarin therapy.

– Am J Health Syst Pharm 2000 Jul 1;57(13):1221-7; quiz 1228-30 —
Potential interactions between alternative therapies and warfarin. — Heck AM, DeWitt BA, Lukes AL. — School of Pharmacy and Pharmacal Sciences, Purdue University, Indianapolis, IN, USA.

About 1000 patients were investigated at our clinic during 1991-1995 for occupational skin disease, and 5 had occupational allergic contact dermatitis from spices. The patients were chefs, or kitchen, coffee room, and restaurant workers. All patients had hand (or finger) dermatitis.
– Contact Dermatitis 1996 Sep;35(3):157-62 — Occupational allergic contact dermatitis from spices. — Kanerva L, Estlander T, Jolanki R. — Section of Dermatology, Finnish Institute of Occupational Health, Finland.

Clove cigarettes may be hazardous to your health.
– American Academy of Pediatrics Committee on Substance Abuse: Hazards of clove cigarettes. — Pediatrics. 1991 Aug;88(2):395-6.

The smoking of clove cigarettes has been associated with 13 cases of serious illness in the United States, including hemorrhagic pulmonary edema, pneumonia, bronchitis, and hemoptysis. We describe a patient in whom, after she smoked a clove cigarette, pneumonia complicated by lung abscess developed. Her lung disease may have been caused by aspiration pneumonia as a consequence of pharyngolaryngeal anesthesia from clove cigarette smoke.
– West J Med 1989 Aug;151(2):220-8 — Clove cigarettes. The basis for concern regarding health effects. — Guidotti TL, Laing L, Prakash UB.

A case is presented in which a 7-month-old child developed central nervous system depression, urinary abnormalities and a large anion-gap acidosis after the accidental oral administration of clove oil. Supportive care and gastric lavage were sufficient for total recovery of the patient. Possible mechanisms of the depression and acidosis are discussed, and suggestions for treatment are presented.
– Hum Exp Toxicol 1991 Jul;10(4):291-4 — Clove oil ingestion in an infant. — Lane BW, Ellenhorn MJ, Hulbert TV, McCarron M. — Department of Emergency Medicine, Martin Luther King, Jr., General Hospital, Drew/UCLA School of Medicine.