Efficacy of a Timolol Nasal Spray as a Treatment for Epistaxis in Hereditary Hemorrhagic Telangiectasia (HHT) - (TEMPO)

Inclusion Criteria: * Age \> 18 years * Patients who give voluntary, informed consent and sign a consent form. * Patients affiliated with the French universal health care system * Patients treated for HHT, that has been confirmed clinically (presence of at least 3 Curaçao criteria) and/or by molecular biology. * Patients who present epistaxis averaging over 20 minutes in the three months before inclusion, justified by completed epistaxis tally sheets. Exclusion Criteria: * Pregnant women or women who could become pregnant during the study, or during lactation * Patients not affiliated with the French universal health care system * Patients who are protected adults according to the terms of the law (French public health laws). * Refusal to give consent. * Patients whose HHT diagnosis has not be confirmed clinically and/or by molecular biology. * Participation in another therapeutic trial which could interfere with the present trial (investigator jugement). * Bronchial asthma, presence or history of severe chronic obstructive pulmonary disease * Cardiac history : cardiac failure or cardiogenic shock. Atrioventricular block (second or third degrees) not controlled with pace-maker or sinus disease (included sinoatrial block) confirmed by ECG less than one year. Ongoing treatment by calcium antagonists (bépridil, diltiazem, verapamil) or antiarrhytmics (propafénone, quinidine, hydroquinidine, disopyramide) or clonidine or lidocaîne. Ongoing beta-blocker treatment. * Bradycardia (\<50 pulse per minute) * Hypotension (PAS \< 90 Hg mm) * Angina * Not controlled Pheochromocytoma * Severe peripheral circulatory disturbances (Raynaud disease) * Hypersensitivity to the active substance, any of the excipients or other beta-blocking agents * Ongoing treatment by floctafénine or sultopride or amiodarone * Patients who do not complete epistaxis grids for three months before treatment * Patients who present epistaxis averaging below 20 minutes in the three months before inclusion