There have been no Phase III trials conducted with Duodart; however, co-administration information is available from the CombAT (Combination of Avodart and Tamsulosin) study, a comparison of dutasteride 0.5mg and tamsulosin 0.4mg once daily for four years as co-administration or as monotherapy.
Information on the side effect profiles of the individual components (dutasteride and tamsulosin) is also provided.
The most common undesirable effects during combined administration of dutasteride and tamsulosin related to the organ system "Reproductive system and breast". These undesirable effects were observed more frequently with the combination therapy than with the respective monotherapies and in each case were more frequent in the first year of treatment than in the subsequent years of treatment (see Pharmacology under Actions).
The undesirable effects, which were observed either during one of the two monotherapies (in clinical trials and/or during post-marketing surveillance) or in the co-administration study, are listed as follows by organ system and frequency. (See the prescribing information of the single-agent preparations for any assignment of individual undesirable effects to either of the two active ingredients).
The following convention has been chosen for classification of the undesirable effects: very common (≥ 1/10), common (≥ 1/100 and <1/10), uncommon (≥ 1/1000 and < 1/100), rare (≥ 1/10,000 and < 1/1000), very rare (< 1/10,000), unknown (based predominantly on spontaneous reports during post-marketing surveillance, precise frequency cannot be estimated.
Neoplasms: Unknown: Breast cancer in men (see Precautions).
Immune system disorders: Uncommon: Rash, pruritus, urticaria. Rare: Angioedema. Very Rare: Stevens-Johnson syndrome.
Psychiatric disorders: Common: Decreased libido. Very rare: Depressive mood.
Nervous system disorders: Common: Dizziness. Rare: Syncope.
Eyes: Unknown: blurred vision, visual disturbances.
Following market launch, there have been reports of a relationship between the occurrence of what is known as Intraoperative Floppy Iris Syndrome (IFIS) during cataract and glaucoma surgery and treatment tamsulosin (see Precautions).
Cardiovascular disorders: Uncommon: Palpitations, orthostatic hypotension. Unknown: Tachycardia, arrhythmias (e.g. atrial fibrilation).
Respiratory disorders: Uncommon: Rhinitis. Unknown: Epistaxis, dyspnoea.
Gastrointestinal disorders: Uncommon: Nausea, constipation, diarrhoea, vomiting, dry mouth.
Skin and subcutaneous tissue disorders: Unknown: Exfoliative dermatitis, erythema multiforme.
Reproductive system and breast disorders: Common: Impotence, ejaculation disorders (such as retrograde ejaculation), gynaecomastia, breast tenderness. Very rare: Priapism, testicular pain and testicular swelling. Unknown: Persistent sexual dysfunction (such as impotence, ejaculation disorders and decreased libido) even after discontinuation of therapy.
General disorders: Uncommon: Asthenia.