| Oilatum Junior Emollient Bath Additive | - |  29/04/16 |  10/07/15 | Light Liquid Paraffin | GlaxoSmithKline Consumer Healthcare (Ireland) Ltd |
| Oilatum Junior Flare-Up Bath Additive | - | 29/04/16 | 07/11/16 | Benzalkonium Chloride, Light Liquid Paraffin, Triclosan | GlaxoSmithKline Consumer Healthcare (Ireland) Ltd |
| Oilatum Plus Bath Additive | - | 03/05/16 | 26/10/17 | Benzalkonium Chloride, Light Liquid Paraffin, Triclosan | GlaxoSmithKline Consumer Healthcare (Ireland) Ltd |
| Oilatum Shower Gel 70% w/w Gel | - | 01/11/16 | 10/07/15 | Light Liquid Paraffin | GlaxoSmithKline Consumer Healthcare (Ireland) Ltd |
| Olanzapine Mylan 2.5 mg, 5 mg, 7.5 mg, 10 mg, 15 mg & 20 mg film-coated tablets | - | 08/08/19 | 07/08/19 | Olanzapine | Gerard Laboratories |
| Olmesartan Amlodipine Mylan - 20mg/5mg, 40mg/10mg, 40mg/5mg | - | 29/08/19 | 29/08/19 | Amlodipine besilate, olmesartan medoxomil | Gerard Laboratories |
| Olmesartan medoxomil 10mg, 20mg & 40mg Film-coated tablets | - | 29/08/19 | 07/02/19 | olmesartan medoxomil | Gerard Laboratories |
| Olumiant 2 mg and 4 mg Film-Coated Tablets | | 10/09/18 | 02/10/18 | Baricitinib | Eli Lilly and Company (Ireland) Limited |
| Omacor 1000 mg Soft Capsules | - | 02/10/18 | 02/10/18 | 90% Omega-3 acid ethyl esters | Mylan IRE Healthcare Limited |
| Omeprazole Mylan 10mg, 20mg, 40mg gastro-resistant capsules, hard | - | 08/06/17 | 13/06/17 | Omeprazole | Gerard Laboratories |
| Omesar 10mg, 20mg and 40mg Film-Coated Tablets | - | 22/06/17 | 21/03/19 | olmesartan medoxomil | A. Menarini Pharmaceuticals Ireland Ltd |
| Omesar Plus 20 mg/12.5 mg & 20 mg/25 mg Film-coated tablets | - | 27/03/19 | 27/03/19 | Hydrochlorothiazide, olmesartan medoxomil | A. Menarini Pharmaceuticals Ireland Ltd |
| Omesar Plus 40 mg/12.5 mg & 40 mg/25 mg film-coated tablets | - | 27/03/19 | 27/03/19 | Hydrochlorothiazide, olmesartan medoxomil | A. Menarini Pharmaceuticals Ireland Ltd |
| Omnexel | - | 15/07/15 | 21/07/15 | Tamsulosin Hydrochloride | Astellas Pharma Co. Ltd |
| Onbrez Breezhaler 150 microgram inhalation powder, hard capsules | - | 22/01/19 | 17/04/19 | Indacaterol maleate | Novartis Ireland Limited |
| Onbrez Breezhaler 300 microgram inhalation powder, hard capsules | - | 14/03/19 | 17/04/19 | Indacaterol maleate | Novartis Ireland Limited |
| Oncaspar (solution) | | 20/05/19 | 20/05/19 | pegaspargase | Servier Laboratories Ireland Ltd |
| Ondansetron 2mg/ml Solution for Injection or Infusion | - | 20/06/18 | 14/06/19 | Ondansetron hydrochloride dihydrate | Gerard Laboratories |
| One-Alpha 0.25 mcg Capsules | - | 28/10/16 | 24/11/17 | Alfacalcidol | LEO Pharma |
| One-Alpha 1 mcg Capsules | - | 28/10/16 | 16/02/17 | Alfacalcidol | LEO Pharma |
| One-Alpha Drops | - | 17/05/19 | 26/04/19 | Alfacalcidol | LEO Pharma |
| Onglyza 2.5 mg & 5 mg film-coated tablets | - | 24/08/18 | 23/08/18 | Saxagliptin hydrochloride | AstraZeneca Pharmaceuticals (Ireland) DAC |
| Opatanol 1mg/ml eye drops solution | - | 10/04/19 | 08/04/19 | Olopatadine (as hydrochloride) | Novartis Ireland Limited |
| OPDIVO 10 mg/mL concentrate for solution for infusion | | 13/05/19 | 29/05/19 | Nivolumab | Bristol-Myers Squibb Pharma EEIG |
| Opsumit 10mg | - | 06/12/18 | 05/10/18 | Macitentan | Actelion Pharmaceuticals UK Ltd |
