Drug combination of PDE3/PDE4 inhibitor and muscarinic receptor antagonist

1. A nebulizer inhaler, a dry powder inhaler or a metered dose inhaler comprising:

(i) a composition which comprises (a) a therapeutically effective amount of a PDE3/PDE4 inhibitor which is 9,10-Dimethoxy-2-(2,4,6-trimethylphenylimino)-3-(N-carbamoyl-2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one or a pharmaceutically acceptable acid addition salt thereof, and (b) a therapeutically effective amount of a muscarinic receptor antagonist which is selected from the group consisting of atropine, methylatropine, homatropine, hyoscyamine, hyoscine, glycopyrrolate, ipratropium, oxitropium, clidinium and mepenzolate; and

(ii) one or more pharmaceutically acceptable carriers, diluents, or excipients.

2. A nebulizer inhaler, a dry powder inhaler or a metered dose inhaler composition according to claim 1 , in which the PDE3/PDE4 inhibitor (a) is 9,10-Dimethoxy-2-(2,4,6-trimethylphenylimino)-3-(N-carbamoyl-2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one.

3. A nebulizer inhaler, a dry powder inhaler or a metered dose inhaler composition according to claim 1 or 2 , in which the muscarinic receptor antagonist (b) is atropine, hyoscine, glycopyrrolate, ipratropium or oxitropium.

4. A nebulizer inhaler, a dry powder inhaler or a metered dose inhaler composition according to claim 1 , in which the muscarinic receptor antagonist (b) is atropine or glycopyrrolate.

5. A nebulizer inhaler, a dry powder inhaler or a metered dose inhaler composition according to claim 1 , wherein the composition is a fixed combination.

6. A method of treating a disease or condition which is based on acute or chronic obstruction of bronchi or vessels in the respiratory tract, in a subject in need thereof, which method comprises administering by inhalation to said subject (a) a therapeutically effective amount of a PDE3/PDE4 inhibitor which is 9,10-Dimethoxy-2-(2,4,6-trimethylphenylimino)-3-(N-carbamoyl-2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one or a pharmaceutically acceptable acid addition salt thereof, and (b) a therapeutically effective amount of a muscarinic receptor antagonist which is selected from the group consisting of atropine, methylatropine, homatropine, hyoscyamine, hyoscine, glycopyrrolate, ipratropium, oxitropium, clidinium and mepenzolate.

7. A method according to claim 6 , wherein the muscarinic receptor antagonist is selected from the group consisting of atropine, hyoscine, and glycopyrrolate.

8. A method according to claim 6 , wherein the disease or condition is asthma or chronic obstructive pulmonary disease (COPD).

9. A method according to claim 6 , wherein said subject is a human.

10. A method of treating a disease or condition in a subject in need thereof, which method comprises administering by inhalation to said subject (a) a therapeutically effective amount of a PDE3/PDE4 inhibitor which is 9,10-Dimethoxy-2-(2,4,6-trimethylphenylimino)-3-(N-carbamoyl-2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one or a pharmaceutically acceptable acid addition salt thereof simultaneously, separately or sequentially in combination with (b) a therapeutically effective amount of a muscarinic receptor antagonist which is selected from the group consisting of atropine, methylatropine, homatropine, hyoscyamine, hyoscine, glycopyrrolate, ipratropium, oxitropium, clidinium and mepenzolate,

wherein the disease or condition is selected from the group consisting of asthma, allergic asthma, bronchitis, emphysema, bronchiectasis, chronic obstructive pulmonary disease (COPD), adult respiratory distress syndrome (ARDS), steroid resistant asthma, severe asthma and pediatric asthma.